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THE 

MANUFACTURE  OF  LEATHER: 


DESCRIPTION  OF  ALL  OF  THE  PROCESSES  FOR  THE  TANNING  AND  TAWING  WITH 
BARK,  EXTRACTS,  CHROME  AND  ALL  MODERN  TANNAGES  IN  GENERAL  USE, 


AND  THE 


CURRYING,  FINISHING  AND  DYEING  OF  EVERY  KIND  OF  LEATHER  ; 

INCLUDING  THE  VARIOUS  RAW  MATERIALS,  THE  TOOLS,  MACHINES,  AND 
ALL  DETAILS  OF  IMPORTANCE  CONNECTED  WITH  AN  INTELLIGENT 
AND  PROFITABLE  PROSECUTION  OF  THE  ART, 

WITH  SPECIAL  REFERENCE  TO  THE  BEST  AMERICAN  PRACTICE. 

TO  WHICH   ARB  ADDED 

LISTS  OF  AMERICAN  PATENTS   (1884-1897)  FOR  MATERIALS,  PROCESSES, 
TOOLS,  AND  MACHINES,  FOR  TANNING,  CURRYING,  ETC. 

BY 

CHARLES  THOMAS  DAVIS. 

SECOND  EDITION,  REVISED  AND  IN  GREAT  PART  REWRITTEN. 

ILLUSTRATED  BY  ONE  HUNDRED  AND  FORTY-SEVEN  ENGRAVINGS  AND  FOURTEEN  SAMPLES 
OF  QUEBRACHO  TANNED  AND  ANILINE  DYED  LEATHERS. 


PHILADELPHIA  : 
HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 
810  WALNUT  STREET. 

LONDON : 
SAMPSON  LOW,  MARSTON  &  CO.,  Ltd., 

ST.  DUNSTAN'S  HOUSE,  FETTER  LANE,  FLEET  STREET,  E.  C. 
1897. 


Copyright,  by 
CHARLES  THOMAS  DAVIS, 
1897. 


Printed  at  the 
WICKERSHAM  PRINTING  HOUSE, 
53  and  55  North  Queen  Street, 
Lancaster,  Pa.,  U.  S.  A. 


THE  GETTY  CENTER 


Go 

MY  FRIEND, 

JAMES  E.  MOONEY, 

PRESIDENT  OF  THE  AMERICAN  OAK  LEATHER  CO.,  CINCINNATI,  OHIO, 

WHO  HAS  DEVOTED  HIS  LIFE  TO  THE  MANUFACTURE  OF  LEATHER  OF 
ALL  KINDS,  AND  HAS  DONE  MORE  THAN  ANY  OTHER  MAN  TO 
BRING  TANNING  EXTRACTS  INTO  GENERAL  USE, 

I  Dedicate  this  Book. 


PREFACE 


TO  THE  SECOND  EDITION. 


After  nearly  two  years  spent  in  the  thorough  revision,  and 
the  almost  re-writing  of  this  book,  necessary  on  account  of  the 
many  improvements  in  the  manufacture  of  leather,  the  time 
has  come  to  prepare  the  preface. 

The  object  which  the  author  has  kept  constantly  in  view  has 
been  to  supply  his  readers  with  practical  and  useful  informa- 
tion upon  such  subjects  as  come  within  the  scope  of  the  book, 
and  in  as  condensed  a  form  as  possible.  He  has  given  no  space 
to  mere  theorizing,  as  he  feels  that  he  can  be  of  greater  use  in 
setting  forth  good  technical  information,  combined  with  suita- 
ble illustrations.  The  reader  of  a  work  of  this  character  is 
necessarily  looking  for  help  in  his  particular  field  of  industry, 
and  is  much  better  pleased  to  find  the  subject  clearly  expounded 
than  to  wade  through  pages  of  purely  theoretical  matter. 

The  tanner's  trade,  like  most  other  trades,  has  in  the  past 
been  followed  and  carried  out  by  rule  of  thumb  rather  than  by 
scientific  guidance.  But  this  is  steadily  and  rapidly  changing; 
chemistry  having  become  the  handmaid  of  all  the  industries, 
the  chemist  is  necessarily  a  part  of  the  personnel  of  every 
large  tannery,  and  in  all  departments  of  leather  manufacture 
he  is  making  his  influence  felt  for  good. 

During  the  past  fifteen  years  the  leather  industry  of  the 
United  States  has  made  greater  strides  than  in  all  of  the  pre- 
vious centuries  of  its  existence.  The  chrome  process  has  been 
introduced,  and  tanning  extracts  have  come  into  general  use, 

(v) 


vi 


PREFACE  TO  THE  SECOND  EDITION. 


and  the  world  largely  owes  its  progress,  in  these  directions,  to 
the  United  States.  True,  Germany  led  in  the  theoretical  re- 
search regarding  the  use  of  chrome,  but  it  remained  for  the 
United  States  to  make  this  invention  a  practical  success. 

We  are  ever  traveling  onward,  and  while  it  may  by  some  be 
considered  that  the  duty  of  15  per  cent,  on  hides  and  calf-skins 
might  be  an  impediment,  it  can  readily  be  overcome  by  our 
superior  machinery  and  skill,  and  thus  will  we  be  able  still  to 
hold  our  foreign  trade. 

While  this  industry  has  progressed  from  the  simplest  and 
most  primitive  to  its  present  state,  it  is  not  yet  perfect.  The 
author  would  therefore  admonish  every  manufacturer  of  leather 
to  be  on  the  lookout  for  all  new  improvements,  and  when  found 
to  be  practicable  to  adopt  them,  as  only  in  this  way  can  he 
keep  "up-to-date,"  and  thus  be  saved  from  being  relegated  to 
the  rear.    It  is  much  easier  to  go  backward  than  to  go  forward. 

He  desires  especially  to  acknowledge  his  indebtedness  to 
the  Shoe  and  Leather  Reporter  for  much  valuable  data  gathered 
from  its  columns,  and  to  all  other  trade  papers  from  which  he 
has  taken  any  matter,  not  specially  acknowledged  in  the  body 
of  the  book. 

Charles  Thomas  Davis. 

Washington,  D.  C, 
603  Seventh  Street,  October  i,  iSgj. 


CONTENTS. 


CHAPTER  I. 
Water  and  Pumps. 

PAGE 


Location  of  tanneries  and  currying  shops  in  the  United  States;  Advan- 
tages of  locations  upon  rivers  and  streams ;  Important  position  of 
water  in  tanning ;  Most  important  admixtures  of  water  and  their  in- 
fluence in  tanning  .......       ...  .1 

Distinction  of  water  as  hard  and  soft ;  Admixtures  of  spring  and  well 
water   I' 

Points  to  be  considered  in  determining  the  qualities  of  water  for  tanning 
purposes;  Reasons  for  swelling  or  plumping  hides  intended  for  sole 
leather  3 

Temperature  of  the  water  used  for  preparing  the  hides  :  Methods  for  de- 
termining the  constituents  of  water       .......  4 

Process  of  determining  the  hardness  of  water  by  a  soap  solution    .       .  5 

Determination  of  total  hardness        ........  (i 

Determination  of  permanent  hardness  ;  Softening  water         ...  9 

Use  of  borax  for  purifying  water      .       .       .      .      .      .      .  .10 

Pumps  ;  Prominence  of  pumping  machinery  among  the  various  branches 
of  engineering  ............  12 

Classes  of  pumps  commonly  used  for  raising  water  from  wells  ;  Lifting 
or  atmospheric  pumps  and  their  action  .......  13 

Limit  of  height  to  which  water  can  be  raised  from  wells  by  common  at- 
mospheric pumps  14 

Importance  of  a  uniform  temperature  of  the  water  in  the  manufacture 
of  waxed  calf ;  The  Pohle  system  of  pumping  water  by  compressed 
air  15 

The  Pohle  Air  Lift  Plant  at  the  works  of  the  Henr_v  Lang  Co.,  Newark, 
N.  J.,  described  and  illustrated  19 


CHAPTER  II. 
Animal  Skin. 

Classes  of  raw  products  with  which  the  tanner  has  to  deal ;  Structure  of 
the  animal  skin  ;  Composition  of  the  epidermis  ..... 

(  vii  ) 


Vlll 


CONTENTS. 


PAGE 


On  what  the  quality  of  the  leather  which  can  be  produced  from  a  skin 

depends;  A  transverse  section  of  the  skin,  described  and  illustrated  .  22 
Conversion  of  the  connective  tissue  fibres  into  glue         .       .       .  .23 
Behavior  of  skins  under  various  conditions;  Chemical  and  morpholog- 
ical constitution  of  the  skin   24 

Preparation  of  cori'in   25 

Swelling  influences  of  natural  waters  upon  the  coriin;  Effect  of  too 

long  liming   26 

Preparation  of  connective-tissue  substance       ......  27 

Swelling  influence  of  acids  upon  the  skin  fibres   28 


CHAPTER  III. 

Vegetable  Tanning  Materials. 


Rutea ;  Kino ;  Malabar  or  East  Indian  kino  ;  Gambier ;  Catechu  or 

terra  japonica  29 

Gall-nuts  30 

Galls  (Knopperu);  Chinese  gall-nuts;  Rove;  Sumach  ;  .Sicilian  sumach  ; 

Italian  sumach   .       .  .31 

Spanish  sumach ;  Tyrol  sumach  ;  French  sumach  ;  Tezera  sumach  ; 

American  sumach  ;  Swedish  sumach  ;  Valonia     .       .       .       .  .32 
Divi-divi ;  Myrobalans  ;  Bublah  ;  Logwood  ;  Fustic        .       .       .  .33 
Weld  ;  Larch  bark  ;  Fir  bark  ;  Hemlock  bark  ;  American  hemlock  ex- 
tract ;  Oak  bark  34 

Canaigre   35 

Prof.  Forbes  on  the  value  of  canaigre  tanning  materials;  Quebracho  .  36 
Discovery  of  the  valuable  tanning  properties  of  quebracho ;  Home  of 

the  quebracho  tree  37 

Prof.  Eituer  on  the  uses  of  quebracho                      .....  38 
Sample  of  leather  tanned  with  quebracho  extract ;  Analysis  of  que- 
bracho  39 

Statistics  of  exports  of  quebracho  from  the  Argentine  Republic  ;  Statis- 
tics of  the  American  export  trade  in  sole  leather  to  Germany  ;  Forests 
of  quebracho  trees  in  the  Argentine  Republic       .       .       .       .  .40 

Advantages  of  the  use  of  quebracho  ;  Process  for  using  pure  quebracho 

wood  for  sole  leather  in  Buenos  Ayres  ;  First  or  coloring  liquor  .       .  41 
Second  liquor;  Third  liquor;  Method  for  employing  quebracho  with 
oak  bark  for  sole  leather  in  Europe       .......  42 

Loss  in  export  trade  in  sole  leather  of  the  United  States  .       .       .  .43 

Cost  of  quebracho  bark  ;  Palmetto  root  44 

Chestnut  oak  wood  ;  Walnut  bark  ;  Lombardy  poplar  bark  ;  Elm  bark; 
Horse-chestnut  bark  ;  Phyllocitannic  acid  ;  ^5Jsculotannic  acid  .       .  45 


CONTENTS. 


IX 


PAGE 

Horse-chestnut  extract ;  Willow  bark  ;  Alder  bark  ;  Beech  bark  ;  Pro- 
tacese  barks;  Snouba  bark  (scorza  rosa)        ......  46 

Ratanky  root ;  Avens  root ;  Tormentil  root ;  Sassafras  root ;  Geranium 
Wallachianum  ;  Mesquite  oak  and  live  oak  barks  ;  Mimosa        .       .  47 

CHAPTER  IV. 

Leaching;  The  Barkometer  ;  Hark  Mills;  Bark  Conveyer;  The 

Tan  Press. 


Cardinal  points  to  be  considered  in  leaching    ......  48 

The  gravity  system  generally  employed  by  American  tanners  and  ex- 
tract makers  ;  Illustration  of  the  most  common  way  of  leaching  ;  Ab- 
solute necessity  of  slow  leaching    ........  49 

General  rule  for  the  head  leach  ;  The  ideal  leach    .       .       .       .  .50 

The  most  seriously  defective  system  of  leaching      .       .       .       .  .5] 

Leach  pumps  of  the  Vaughn  Machine  Co.,  Peabody,  Mass.;  Regula- 
tion of  the  temperature  of  the  liquors  in  leaching       .       .       .  .52 

The  problem  of  properly  leaching  bark     .......  53 

How  the  difficulty  of  packing  may  be  overcome  ;  Manner  of  pumping  .  54 
Taking  advantage  of  the  factor  "percolation  ;"  Limit  to  the  length  of 

the  column  in  any  one  leach  ;  Advantage  of  ten  or  more  leaches       .  55 
Temperature  of  the  water  or  liquor  on  the  tail  leaches  ;  Check  on  the 
efficiency  of  the  leaching        .........  56 

Loss  in  tanning  substance  of  the  bark  in  the  layaways;  Use  of  the  spent 
liquor  from  "rockers"  on  the  tail  leach  ;  Object  of  applying  a  mel- 
low liquor,  weak  in  tanning  substance,  to  a  green  hide  from  the  beam 

house  57 

System  of  leaching  bark  in  use  by  the  American  Oak  Leather  Co.,  Cin- 
cinnati, Ohio  ;  Stephen  Dow  &  Co.,  and  E.  C.  Cottle  &  Son,  and 
Beggs  &  Cobb's  systems  of  leaching  hemlock  bark      .       .       .  .58 

Preference  for  pumping  leaches  more  frequently  ;  Flooding  leaches  ; 
Great  attention  paid  to  the  grinding  of  bark  .       .       .       .       .  .59 

Ledger  account  for  each  leach  ;  The  Press-leach  system  .       .       .  .60 

The  barkometer  and  its  application  ........  62 

Bark  mills  ;  The  earliest  patent  for  a  bark  mill  awarded  to  C.  Foss       .  63 
A.  Bull's  patent ;  Main  object  in  grinding  bark  ;  Fads  in  the  bark  busi- 
ness      .............  64 

Reform  brought  about  by  Dr.  H.  E.  Starcke's  analyses  of  "spent  tan  "  .  65 
Various  constructions  of  bark  mills  ;  Bark  cutter  (Jones'  patent)  made 

by  the  Vaughn  Machine  Co.,  Peabody,  Mass  66 

Automatic  knife  grinder  for  the  Jones  patent  bark  cutter  and  other  cut- 
ters ;  Bark  conveyer  patented  by  Oliver  A.  Zane,  of  Peabody,  Mass   .  68 
The  tan  press  made  by  William  F.  Martin,  .Salem,  Mass.       .       .  .71 


X 


CONTENTS. 


CHAPTER  V. 

Tanning  Extracts. 

PAGE 

Growth  in  the  use  of  extracts  ;  Tanning  extracts  in  common  use  in  the 
United  States  ;  Manufacture  of  tanning  extract  from  the  chestnut  tree 
and  chestnut  oak  tree      ..........  74 

Concentration  of  the  liquor  in  the  vacuum  pan       .       .       .       .  .75 

Preparation  of  hemlock  extract ;  Boiling  point  of  water  ;  Similarity  of 
the  manufacture  of  tanning  extracts  to  the  process  of  extracting  sugar.  7(i 

Decolorization  of  the  liquor  before  concentration  ;  Examination  of  tan- 
ning extracts   .       .       .  .77 

CHAPTER  VI. 

Soaking  and  Softening. 

Process  of  soaking  hides  as  recommended  by  a  German  tanner  ;  Soak- 
ing hides  in  w  heels  and  in  a  water-pit  or  box       .       .       .       .  .78 

Preparation  of  hides  and  skins  for  soaking       ......  79 

Treatment  of  foreign  salted  hides  and  skins,  dry  salted  hides,  kips,  etc., 
and  dried  hides  and  skins       .       .       .       .       .       .       .       .  .80 

Reasons  for  the  neglect  by  tanners  of  foreign  hides  and  skins  ;  Neces- 
sity of  the  preparatory  work  being  thorough        .       .       .       .  .81 

Usual  mode  of  softening  dry  hides  for  sole  leather  ;  Chemical  soak  ;  Di- 
rections for  working  various  kinds  of  hides  ......  82 

Use  of  borax  for  softening  water  ;  Use  of  pure  water  in  the  soaks  .       .  83 

Time  required  for  soaking  calf-kid  and  light  hides  ;  Softening ;  Hide 
mills  and  their  construction  ;  Softening  mill  in  use  by  the  morocco 
and  kid  tanners  of  Philadelphia,  Penna.  84 

CHAPTER  VII. 

Deputation  or  Unhairing. 

Definition  of  a  depilatory;  Depilous  skins;  Different  methods  for  ac- 
complishing depilation  ;  Preparation  and  properties  of  lime       .       .  86 

Objections  to  the  use  of  lime     .........  87 

Restoration  of  the  suppleness  to  upper,  morocco  and  other  kinds  of 
leather  ;  Bating  ;  Recapitulation  of  the  inconveniences  of  the  liming 
process ;  Raising  88 

Primitive  manner  of  removing  the  hair  ;  Necessity  of  properly  prepar- 


CONTENTS.  xi 

PAGE 

ing  the  hides  or  skins  for  the  beam  house  ;  Proper  condition  of  hides 
for  limed  stock  ;  Neglect  of  the  work  at  the  lime  pits  .       .       .  .89 

Proper  treatment  of  calf-skins  in  the  limes  ;  Replacement  of  lime  in  de- 
pilating by  acid  liquors  90 

Construction  and  arrangement  of  lime  vats;  Preparation  of  a  new  vat; 
Dead,  weak  and  live  vats  91 


Operation  of  raising  ;  Time  employed  for  liming  ;  The  power  reel ; 
American  practice  of  putting  hides  through  the  soaks  and  limes  ;  Im- 
possibility of  giving  exact  or  arbitrary  rules  for  liming  and  handling.  92 

Arsenic  and  its  use  in  lining  of  goat  skins  ;  Economies  and  improve- 


ments in  lining  and  bating  93 

Use  of  lime  and  dog-pure  in  the  beam  house  ;  Action  of  the  lime ;  Re- 
moval of  grease  in  the  lining  of  sheepskins         .       .       .       .  .94 
The  disease  known  as  itch  and  objection  to  scabby  skins       .       .  .95 

The  white  itch  and  its  cause  96 

Depilating  with  sodium  sulphide  ;  Prof.  Fiebing  on  this  subject      .       .  97 
Method  of  using  sodium  sulphide  in  connection  with  lime     .       .  .98 
Enumeration  of  the  advantages  obtained  by  the  use  of  sodium  sulphide  99 
On  what  the  value  of  sodium  sulphide  as  a  depilatory  depends  ;  John  W. 
Stevenson  on  the  sulphide  of  sodium  process       .....  100 

Method  of  using  sulphide  of  sodium  as  a  depilating  agent  .       .  102 

Most  striking  effect  of  sulphide  of  sodium  in  the  limes  ;  Explanation  of 
the  property  of  sulphide  of  sodium  of  bringing  back  the  grain  to  its 
fresh,  green  state    ...........  104 

Summary  of  the  good  qualities  of  sulphide  of  sodium  ;  Undesirable 
qualities  of  sulphide  of  sodium      ........  105 

Aging  of  alum-tawed  glove-kid  .........  10(1 

Reasons  why  a  green  skin  is  flat  and  unelastic  as  compared  to  well- 
tanned  leather  ;  A  German  opinion  on  the  use  of  sulphide  of  sodium  107 
Main  requisite  demanded  of  a  depilatory  ;  Arseuic  as  a  depilatory  .       .  108 
Combination  of  sulphide  of  arsenic  with  lime  ;  Action  of  sulphide  of  so- 
dium and  of  sulphate  of  arsenic  and  lime      ......  109 

Action  of  lime  alone  ;  Rapidity  of  the  action  of  arsenic-lime  .       .       .  110 
Comparison  of  results  obtained  by  arsenic  with  those  obtained  by  sul- 
phide of  sodium       .  .       .       .       .       .       .       .       .  .111 

Constitution  of  the  hide;  Nature  of  the  grain  of  the  hide;  Action  of  de- 
pilatories on  the  true  skin  and  on  the  grain;  Cause  of  the  inner  rotten- 
ness of  leather  112 

Effect  of  allowing  putrefaction  to  progress;  Selection  of  skins  in  the 
beam-house;  Depilating  with  charcoal   .    •    .       .       .       .       .       .  llo 

William  Anderson's  method  of  depilating  with  charcoal;  Depilation 
with  sulphide  of  barium;  Foley's  process     ......  114 

Advantages  of  this  process  over  the  liming  process  115 

Working-out  and  unhairing  all  kinds  of  hides  and  skins  without  limes, 
bate,  drench  or  beaming — the  Peirson-Moor  process;  Chemistry  of  de- 
pilatories  116 


•    xii  CONTENTS. 

PAGE 

Results  of  the  analysis  of  liquor  from  an  old,  well-plunged  lime  pit  117 
Proximate  analysis  of  red  arsenic  ;  Investigation  of  the  part  played  by 

red  arsenic  in  the  mixture  of  it  with  lime      .       .       .       .       .  .118 

Investigation  of  the  depilatory  properties  of  calcium  thioarsenite  .  .  119 
Depilation  by  sweating;  Villon's  experiment  and  conclusions  drawn 

therefrom  120 

The  "cold-sweat"  process  and  the  "warm-sweat"  method;  Cause  of 

"frieze;"  "black  spots  "  or  "old  grain;"  Description  of  a  building 

for  sweating  hides  and  skins  .........  121 

Care  to  be  observed  in  sweating  hides  124 

Effect  of  the  sweating  process;  Advisability  of  the  sweating  process  for 

imported  hides  125 

Method  of  sweating  126 

Operation  of  the  sweating  process;  The  warm-sweating  process  .  .  127 
vSweating  fresh  hides  128 

CHAPTER  VIII. 

Unhairing  and  Fleshing  by  Hand  and  Machinery. 

Interior  view  of  the  beam-house;  The  German  form  of  beam  and  the 
unhairing  knife;  Unhairing  of  hides  and  skins  by  the  hand  method  130 

Injury  to  hires  in  unhairing;  The  "short-hair  knife;"  Beam  work  in 
France  133 

Unhairing  of  slaughtered  calf-skins  fresh  from  the  Paris  market;  Flesh- 
ing by  the  hand  method;  Fleshing  knives  described  and  illustrated  135 

German,  or  spring  fleshers;  Operation  of  fleshing;  The  saw-tooth  flesher, 
described  and  illustrated         .  136 

Turning  steel  described  and  illustrated;  Going  over  the  flesh-sides  with 
the  "worker"  137 

Counter-fleshing;  A  sure  hand  required  to  do  the  fleshing  of  a  calf-skin; 
Soaking  hides  after  fleshing  by  the  hand  process  .....  138 

Soaking  hides  in  a  steeping  cistern  after  fleshing;  How  long  should  the 
hides  soak  after  fleshing,  and  what  indicates  their  readiness  for 
scouring  139 

Fleshing  and  unhairing  by  machinery;  The  Vaughn  improved  fleshing, 
unhairing  and  working-out  machine,  illustrated  and  described   .       .  140 

The  cylinders  used  with  this  machine,  illustrated;  Grinding  lathe  or 
cylinder  and  roll  sharpening  and  turning- up  machine  made  by  the 
Vaughn  Machine  Co.,  described  and  illustrated   .....  144 

Unhairing  machines  ;  Whitney's  "  Jumbo  "  unhairing  machine     .       .  146 

Whitney's  patent  combined  unhairing,  fleshing  and  working-out  ma- 
chine  147 

Whitney's  patent  re-fleshing  machine       .......  149 

Practical  success  of  the  unhairing  and  fleshing  machines.       .       .       .  151 


CONTENTS. 


Xlll 


CHAPTER  IX. 

Bating. 

PAGE 


Various  terms  applied  to  this  process  ;  Reasons  why  the  greatest  risk  in 

an}' beam-house  is  that  of  bating   ........  153 

Scientific  investigation  within  recent  times  of  the  processes  connected 

with  the  tanner's  art;  Objections  to  the  use  of  manure  bate;  Action  of 

manure  bate    ............  154 

Bran  bate;  Necessity  of  removing  the  lime  or  other  alkaline  depilatories 

from  hides  and  skins  previously  to  tanning;  Substitutes  proposed  and 

patents  covering  processes  for  bating   .  155 

C.  T.  Bate  (coal-tar  bate)  invented  by  Peter  S.  Burns  and  Chas.  S.  Hull 

and  manufactured  by  the  Martin  Dennis  Chrome  Tannage  Co.;  Other 

acids  proposed  for  bating  purposes        .......  15G 

"  Borol;"  P.  HaufFs  patent ;  Manner  of  bating  ;  Suggestions  regarding 

the  old  form  of  manure  bates;  Bating  high-limed  goat  skins  .  .  157 
Fermeutive  action  of  the  bate;  Best  time  for  fine-hairing;  Best  bate  for 

calf  kid  and  sides;  Borax  and  boracic  acid  as  bates;  Purpose  of  puring 

light  leathers  ............  158 

Method  of  puring;  Consequence  of  leaving  any  lime  in  the  stock  .  .  159 
Treatment  of  hides  intended  for  sole  leather;  Bating  dressing  leather  in 

the  United  States;  Bate  for  sole  leather  160 

Universality  of  the  practice  of  reducing  the  hide  or  skin  and  objections 

to  that  practice   .  161 

Puring  sole  leathers;  Inability  of  getting  colors  right  in  glove  leathers 

due  to  poor  bating  .       .       .       .       ."      .       .       .       .       .  .162 

Properties  of  dog  excrements;  Preparation  of  dog- pure;  Theory  of  dung 

bating  163 

Various  substances  employed  as  bates;  Objections  to  the  present  method 

of  bating;  Usual  method  of  bating.        ...        ....  164 

England  wheels  for  agitating  the  bate  liquor;  Scouring;  Graining;  Final 

soaking  before  placing  the  hides  in  the  ooze  166 


CHAPTER  X. 

Handling  and  Plumping. 

Handling;  Various  methods  of  handling  hides;  Handling  and  transfer- 
ring the  sides  by  the  medium  of  a  revolving  device,  such  as  a  reel     .  167 

Modes  of  connecting  the  sides;  The  hand  reel;  The  rocker  handler;  Ap- 
paratus invented  by  L.  C.  England,  described  and  illustrated     .       .  168 

Paddle  wheels  for  handling  and  vats  in  which  they  revolve    .       .       .  17(1 

Some  European  methods  of  handling;  Handling  the  sides  in  the  manu- 


xiv 


CONTENTS. 


facture  of  grain  and  split  leather;  Handling  by  means  of  a  large  revolv- 


ing drum;  Gorsline's  apparatus  for  handling        .....  172 

Plumping;  Plumping  by  means  of  sour  liquor  ......  173 

Distillation  of  the  sour  liquors  as  proposed  by  H.  J.  Botchford       .       .  174 
Plumping  by  means  of  sulphuric  acid  ;  Introduction  of  this  process  by- 
David  Mac  Bride   175 

Properties  of  sulphuric  acid       .........  170 

Plumping  by  means  of  acetic  acid      .   177 

Mineral  acids  for  plumping;  Lactic  acid  for  plumping     ....  17K 


CHAPTER  XI. 
Laying-away. 

Action  of  tannin;  Probability  of  leather  not  being  a  chemical  combina- 
tion of  the  animal  substance  with  the  tanning  substance;  Mr.  Kuapp's 


experiments  in  making  leather  without  tanning  elements  .  .  .  179 
Final  step  in  the  process  of  tanning  heavy  hides  and  sides;  Laying  away 

the  stock  ,  181 

Layers  and  periods  for  tanning  the  heaviest  sole  leather  in  this  country; 

Laying  away  the  packs  in  the  manufacture  of  finer  grades  .  .  .182 
Various  methods  of  passing  the  liquor;  Jack  for  raising  whole  hides  up 

in  the  lay-away  vats  183 

Float  for  whole  hides  ;  Handling  the  sides  in  tanning  heavy  upper 

leather  184 

CHAPTER  XII. 

Stoning. 

Stouing-jack  made  by  J.  T.  Freeman  &  Co.,  Woburn,  Mass    .       .       .  185 


CHAPTER  XIII. 

Splitting  Leather. 

Perspective  view  of  the  cellar  of  an  upper  leather  tannery;  Splitting 
machines;  Splitting  machine  patented  by  Alpha  Richardson;  Early 
invention  of  Seth  Boyden       .       .       .       .       .       .       .       .       .  18t! 

Richardson's  Union  Splitting  Machine;  The  Belt  Knife  Splitting  Ma- 
chine invented  by  Joseph  F.  Flanders  and  Jere  A.  Marden;  Perspec- 
tive view  of  the  Union  Splitting  Machine;  Attachment  patented  by 
John  A.  Enos;  Leather-splitting  as  generally  practiced        .       .  .INK 


CONTENTS.  XV 

PAGE 

Details  of  Enos's  invention   190 

Leather-splitting  machine  embodying  Enos's  invention  ....  191 

Remedy  of  difficulties  in  splitting  •  192 

Hints  for  splitting  with  the  Union  .Splitting  Machine      ....  193 

The  Belt  Knife  Leather  Splitting  Machine   194 

Instructions  in  regard  to  splitting  leather        ......  198 

Bassett's  belt  knife  splitting  machine;  Improvement  on  grinder  rigging 

for  belt  knife  splitting  machines  ■  201 

Removing  the  rubber  roll  from  the  Bassettt  belt  knife  splitting  ma- 
chine      ............        .  202 

Robertson's  grinding  adjustment  for  belt  knife  splitting  machines.       .  203 


CHAPTER  XIV. 

Scouring. 

Treatment  of  the  leather  after  it  has  been  split;  Tools  used  in  the  hand 


method  of  scouring  leather    ...        ......  208 

Monk's  scouring  machine  and  the  leathers  on  which  it  can  be  nsed  .  209 
Scouring  and  setting  out  machine  built  by  the  Vaughn  Machine  Co., 

Peabody,  Mass.   212 


CHAPTER  XV. 

Stuffing  Leather  ;  Oils  and  Fats  ;  Testing  Oii^s  ;  Water  Proof- 
ing Leather. 

Hand  stuffing  ;  Tempering  upper  leather  ;  When  the  hand  process  of 
stuffing  leather  is  accomplished  ;  Objections  to  the  hand  method  of 


stuffing  215 

Drum  stuffing;  The  best  material  to  use  in  stuffing;  Heating  the  drum  .  216 
Filling  the  drum;  Removing  the  goods;  Setting  the  goods;  Stoning      .  217 

Reed  and  Winchester's  stuffing  drum  218 

Improvement  in  tramping  drums  invented  by  Dr.  Friederich  Knapp  .  220 
Freeman's  stuffing  drum;  Curriers'  oils  and  greases;  Definition  of  oils  .  221 
Three  different  classes  of  bodies  embraced  in  the  name  oil;  Fixed  or 

fatty  oils;  Volatile  and  essential  oils;  Mineral  oils;  Properties  of  fats  .  222 

Most  common  and  abundant  fats;  Cod  oil  223 

Adulterants  of  cod  oil;  Chief  seats  of  the  cod  fishery;  Classification  for 

cod  liver  oil;  Chemical  and  physical  characteristics  of  dark  brown  or 

tanner's  cod  oil       ..........  224 

Detection  of  adulteration  of  cod  oil  with  mineral  oils,  brown  seal  and 

menhaden  oils;  Use  of  Bank  and  .Straits  oils  as  substitutes  for  cod  oil.  225 


XVI 


CONTENTS. 


PAGE 

Degras;  English  sod  oil  226 

French  moellon  oil;  Tallow;  Oleo-stearine  ;  Paraffine  wax  ;  Principal 
stuffing  used  for  upper  leather       ........  227 

The  "  Ideal  "  grease;  Neatsfoot  oil;  Menhaden,  Straits  or  Bank  oil;  Men- 
haden fisheries;  Preparation  of  the  oil   .......  228 

Porpoise  oil ;  Tunny  oil;  Neatsfoot  oil       .......  229 

Degras;  Manufacture  of  degras  in  France;  Mixture  of  degras  and  fish 
oil  280 

Vickers'  degras;  Early  use  of  sod  oil  or  French  degras;  Former  manu- 
facture of  sod  oil;  Injurious  effect  of  the  sulphuric  acid  used  in  mak- 
ing sod  oil;  Method  of  getting  rid  of  an  excess  of  acid  in  sod  oil.       .  231 

Method  used  in  France  for  tanning  oil-dressed  leather  and  for  making 
sod  oil;  American  process  of  oil  dressing       ......  232 

European  method  of  oil  dressing  233 

The  most  valuable  and  characteristic  property  of  genuine  sod  oil;  The 
tanning  principle  of  pure  sod  oil ;  Amount  of  tanning  principle  in 
menhaden,  Bank  and  Straits  oils,  and  in  genuine  cod  oil  .       .  234 

On  what  the  value  of  fish  or  cod  oil  as  a  leather  lubricant  depends; 
Paraffine  wax  .       .       .       .       :  235 

Glycerine;  Changes  created  by  the  introduction  of  mineral  salts  in  the 
manufacture  of  leather  236 

Production  of  glycerine;  Properties  of  glycerine;  Use  of  glycerine  for 

oiling  in  the  place  of  fat  or  degras     .......  237 

Necessity  of  mixing  glycerine  with  supplementary  ingredients;  Methods 
for  effecting  a  better  adherence  of  the  glycerine  to  the  leather   .       .  238 

Combination  of  glycerine  with  tannin;  Practical  method  of  stuffing  with 
glycerine   239 

Testing  oils;  Simple  tests  for  determining  the  amount  of  compounding  240 

Evil  effects  of  the  bad  conditions  of  fats:  Mode  of  distinguishing  a  gen- 
uine degras  from  simple  fat  emulsions  ;  Most  usual  adulteration  of 
degras  241 

Borax;  steam  jacket  kettles;  Stuffing  or  fat  liquoring  with  Palermo  fig 
soap  ..............  242 

Formula  for  making  fat  liquors  with  Palermo  fig  soap;  Fat  liquors       .  243 

Chromol  fat  liquors  for  chrome  tanned  leather,  directions  for  use; 
Water-proof  stuffing   .  244 

Water-proofing  leather;  The  mineral  process;  Stuffing  compounds;  Par- 
affine wax  for  giving  leather  the  quality  of  water-resisting  .       .       .  245 

Formulae  for  producing  water-proof  leather     ......  246 

CHAPTER  XVI. 

Setting-out. 

Considerable  amount  of  labor  required  in  setting  heav}'  leathers;  Ston- 
ing-out,  scouring  and  setting-out  machine  built  by  the  Vaughn  Ma- 
chine Co  248 


CONTENTS. 


XVII 


CHAPTER  XVII. 

Whitening  and  Shaving  Leathkr. 

PAGE 

Various  ways  of  whitening;  French  pattern  of  whitening  slicker;  Form 

of  beam  generally  employed  in  currying  shops     .....  250 
Union  whitening  and  buffing  machine  made  by  J.  T.  Freeman  &  Co.  251 
Shaving  machine;  The  Rood  improved  shaving  machine,  manufactured 
by  the  Vaughn  Machine  Co.  .........  254 


CHAPTER  XVIII 


Blacking  Leather. 


Forms  of  blacking  brushes  in  common  use      ......  25(i 

Leather  blacking,  coloring  and  dressing  machine  patented  by  Batch- 
elder,  and  built  by  the  Vaughn  Machine  Co.       .....  257 


CHAPTER  XIX. 

Machines  for  Rolling,  Pebbling,  Glassing  or  Polishing, 
Finishing,  etc. 

The  glazing  machine  one  of  the  first  steam-driven  tools  introduced  into 
the  trade;  The  Bowers  rocker-motion  leather  finishing  machine.       .  263 

Improved  iron  glassing  jack  made  by  J.  T.  Freeman  &  Co.;  Improved 
straight  bed  rolling  or  pebbling  jack  made  by  J.  T.  Freeman  &  Co.  266 

Martin's  improved  machine   267 

The  Knox  improved  inclined  bed  leather  finishing  and  pebbling  ma- 
chine  268 

The  Coombs  pendulum  jack,  made  by  the  Vaughn  Machine  Co.    .       .  271 


CHAPTER  XX. 

Staking  Machines. 

"Hand  method"  staking  machine  built  by  F.  F.  Slocomb  &  Co.       .  273 

Staking  machine  built  by  the  Vaughn  Machine  Co  274 

Staking  machine  built  by  Wm.  F.  Martin,  Salem,  Mass.       .       .       .  275 


XVU1 


CONTENTS. 


CHAPTER  XXI. 


Machine  for  Measuring  Leather. 

PAGE 

Modes  of  selling  leather;  Sawyer's  leather  measuring  machine       .       .  277 
The  Union  leather  measuring  machine      .......  279 

The  Bolton  machine   ...........  281 


CHAPTER  XXII. 

Mineral  Tanning  Substances — "Chrome,"  or  Mineral  Tannage — 
Characteristics  of  Chrome-Tanned  Leather — 
Currying — Dyeing. 


Principal  mineral  substances;  Aluminium  sulphate;  Preparation  of  neu- 
tral aluminium  sulphate;  Properties  of  aluminium  sulphate        .       .  282 

To  make  aluminium  sulphate  containing  free  sulphuric  acid  available 
for  tanning  purposes;  Alum,  its  formation  and  properties    .       .       .  283 

Splitting  up  of  the  alum  in  absorption  by  the  skin  tissue;  Aluminium 
acetate  and  its  properties;  Advantages  claimed  for  aluminium  acetate.  284 

Chromium  salts;  Potassium  bichromate,  its  manufacture  and  properties.  285 

Sodium  bichromate;  Calcium  bichromate,  strontium  and  barium  and 
the  neutral  chromates  of  calcium,  strontium  and  barium;  Chromium 
alum;  Chromic  sulphate        .........  286 

Hyposulphite  of  soda;  Ferric  salts;  Recommendation  in  the  last  century 
of  tanning  with  ferric  salts  by  D'Arcet;  Bordier's  patent;  Attempted 
reintroductiou  by  Knapp  of  tanning  with  ferric  salts   ....  287 

Preparation  of  an  irou  soap;  Common  salt  and  its  importance  in  tan- 
ning; Varieties  and  preparation  of  common  salt   .....  288 

'•  Chrome  "  or  mineral  tannage;  The  first  use  of  bichromates  for  tan- 
ning made  by  Cavalin,  and  his  method;  Impossibility  of  a  practical 
application  of  this  process  289 

Knapp's  patent  for  tanning  with  ferric  salts  and  other  metallic  oxides; 
Patent  for  the  preparation  of  a  basic  ferric  sulphate  and  its  use  for 
tanning  obtained  by  Pfanhauser;  Knapp's  new  method  of  tanning 
with  ferric  salts  290 

New  and  peculiar  features  claimed  for  this  purpose  by  Knapp       .       .  291 

Nature  of  the  leather  prepared  by  Knapp's  process;  Additional  patent 
applied  for  by  Knapp  for  a  somewhat  different  method  of  preparing 
ferric  salt.  292 

Heinzerling's  patented  process  for  quick  tanning  with  chromates  and 
its  execution   293 


CONTENTS. 


xix 


PAGE 


Directions  for  working  the  upper  aud  sole  leather  obtained  by  this  pro- 
cess into  shoes.       ...........  295 

Advantages  of  chrome  leather;  Abandonment  of  the  above  mentioned 
methods  of  tanning  on  account  of  the  defective  quality  of  the  product 
produced  by  them;  Requisite  characteristics  of  the  mineral  tanning 
substance.  296 

Usefulness  of  the  salts  of  aluminium,  iron  and  chromium  ;  The  two 
methods  of  chrome  tanning  now  in  practical  use;  The  two-bath  pro- 
cess and  the  one  bath  process;  The  Schultz  patents  and  the  Dennis 
patent;  Treatment  in  the  Schultz  method      ......  297 

Commercial  leather  of  superior  quality  by  the  Schultz  process  first  made 
by  Robert  H.  Foederer,  of  Philadelphia,  Pa.,  and  Wm.  Zahn,  of 
Newark,  N.  J.;  Simplification  of  the  art  of  chrome  tanning  by  the 
Dennis  "one-bath  "  process  298 

Tanolin  and  its  advantages       .........  299 

Varieties  of  leather  tanned  by  the  Dennis  process;  Necessity  of  circum- 
spection when  embarking  in  the  new  field  of  chrome  tannage     .       .  300 

High  standing  of  American  morocco  and  kid  manufacturers;  Abandon- 
ment of  the  old  currier  style  of  shaving  on  the  wooden  beam  face; 
Rapid  increase  in  chrome  tannage;  Properties  of  chrome  npper  .       .  301 

Competition  of  chrome  tanning  with  bark;  Impetus  to  the  demand  for 
sporting  shoes  ............  302 

Tanning  calf  or  goat  skins  by  tlie  chrome  process  ;  Directions  by  the 
Martin  Dennis  Chrome  Tannage  Co.  for  using  tanolin  on  calf  or  goat 
skins  304 

Tanning  sheep  skins  by  the  chrome  process;  Some  patents  for  chrome 
tannage    .............  306 

Information  regarding  the  Dennis  "  one  bath  "  process  of  chrome  tan- 
nage; Application  by  the  German  tanners  of  chrome  tanning  to  the 
production  of  a  great  variet3-  of  leathers       ......  307 

The  Dennis  tanning  liquor;  Specification  of  the  patent   ....  308 

The  Dennis  process  of  tanning  leather;  Specification  of  the  patent       .  313 

Characteristics  of  chrome  leather  319 

Currying  chrome  leather;  Preparation  aud  use  of  "  fat  liquors  "    .       .  321 

To  prepare  chrome-tanned  leather  for  dyeing;  Patent  granted  to  E. 
Avellis  and  Emil  Koester  of  Berlin,  Germany;  Practical  example  of 
the  process  322 

Dyeing  chrome  leather;  Dyeing  with  neutral  basic  aniline  colors;  Dye- 
ing with  acid  aniline  colors;  Fixing  alizarine  colors;  The  best  "all- 
round"  mordant  to  be  used  on  leather  323 

Dyeing  leather  with  alizarine  colors  ;  H.  Koechlin  and  E.  Knecht's 
method  324 


XX  CONTENTS. 

CHAPTER  XXIII. 

Kid  or  Morocco  Leathers. 

PAGE 

Great  revolution  in  morocco  manufacturing  in  ten  years  by  the  intro- 
duction of  the  new  agent,  chrome;  Patents  issued  to  Augustus  Schultz 


of  New  York  City  326 

Reasons  given  by  Mr.  Schultz  for  taking  out  two  patents;  Assignment 

and  transfer  of  Schultz's  patents  to  various  parties  ....  327 
William  M.  Norris  on  the  advantages  of  chrome  tanning       .       .       .  328 

Preparing  the  skins    .  330 

Lime  vats  in  a  kid  morocco  factory;  Breaking,  fleshing,  unhairing, 

and  slating  machine  331 

Washing  the  skins   .  334 

Influence  of  the  previous  treatment  of  the  raw  pelt  on  the  leather  pro- 
duced by  any  one  of  the  chrome  processes;  Liming  and  deliming; 

Slating  335 

The  bran  drench;  Tawing  according  to  the  Schultz  patent;  Prepara- 
tion of  the  baths;  Test  for  the  completion  of  tanning  ....  330 
Different  constitution  of  the  baths;  Latitude  in  the  amount  of  water  to 

be  used;  Treatment  of  skins  in  a  drum;  The  reel  337 

Reasons  for  using  more  liquor  and  less  concentrated  baths  when  treat- 
ing skins  in  a  reel  rather  than  when  treating  them  in  a  drum;  Prepara- 
tion of  the  second  bath   ..........  338 

Change  in  the  condition  of  the  chromium  of  the  first  bath;  No  effect 
produced  upon  the  skins  by  the  bichromate  of  potash;  The  essential 
discovery  made  by  Schultz;  No  accurate  determination  of  the  chemi- 
cal reactions  which  take  place  in  the  skins   ....        .       .  33'J 

Treatment  of  the  skins  in  the  second  bath;  Opinions  regarding  the  de- 
scriptions given  in  the  two  Schultz  patents    ......  34(1 

Tanning  goat-skins  for  kid  leathers;  Prof.  Samuel  P.  Sadtler's  experi- 
ments with  goat  skins  341 

Indication  of  plumping;  Effect  of  introducing  a  skin  into  an  acidulated 

bath  342 

The  tan-vat  used  in  the  two-bath  method  of  chrome  tannage;  Specifica- 
tion of  Schultz's  first  patent  (No.  291,784)  343 

Specification  of  Schultz's  second  patent  (No.  291,785)     ....  345 

William  M.  Norris  on  Schultz's  patents  34(5 

Further  information  by  Mr.  Schultz  about  his  process;  First  bath;  Sec- 
ond bath  ■  347 

Advantages  of  making  leather  by  the  Schultz  process      ....  348 

Specification  of  the  Zahn  patent   349 

Explanation  of  chemical  symbols     ........  351 

Reactions  which  take  place  in  preparing  the  chrome  bath;  Rule  for 
finding  the  combining  weight  of  bichromate  of  potash       .       .       .  352 


CONTENTS. 


xxi 


PAGE 

Function  of  the  acid  in  the  bath  353 

Rule  for  determing  the  proper  amount  of  acid  to  use  in  connection  with 

the  hyposulphite  of  soda;  Determination  of  the  proper  relation  between 

the  bichromate  of  potassium  and  the  hyposulphite  of  soda  .  .  .  354 
Sensitive  condition  of  skins  when  saturated  with  chromic  acid;  Troubles 

due  to  the  sulphurous  acid   355 

Putting-out  machine;  Object  of  putting-out;  Vaughn's  machine  for 

putting-out      ............  356 

Shute  and  Faulkner's  seasoning  machine  358 

Formula  for  seasoning  360 

Plans  of  the  kid  factory  of  F.  Blumenthal  &  Co.,  Wilmington,  Del.  .  361 
India  tanned  goat;  Sumac  tanned  skins;  Drying  loft  in  a  morocco 

factory  364 

Finishing  imitation  of  French  kid     ........  366 

Finishing  room  in  a  morocco  factory       .......  367 

Finishing  brushed  kid;  Finishing  straight-grained  goat  ....  368 

View  of  drying  loft  in  a  morocco  factory — showing  the  skins  spread 

out  370 

Graining  and  the  graining  board       ........  371 

Rolling  and  glazing  room  in  a  morocco  factory  372 

Finishing  pebble-grain  goat;  Finishing  oil-goat  .....  373 
Coloring;  Information  about  coloring  by  William  M.  Norris  .       .       .  374 

Dongola  calf   375 

The  old  processes  of  converting  goat  skins  into  Dongola  and  other  fine 

leathers;  Different  processes  through  which  goat-skins  pass  in  their 

conversion  into  Dongola;  Soaking  376 

Milling;  Liming;  Unhairing;  Bating  377 

Slating;  Tanning;  .Striking-out;  Dyeing  or  blacking;  Drying  .       .       .  378 

CHAPTER  XXIV. 

Oak-Tanned  Sole  Leather — Unscoured  and  Scoured 
Leather— Cut  Soles. 

Hides  used;  Placing  the  hides  in  the  soaks;  Changing  the  water  in  the 
soaks;  Liming  379 

Graining;  Advantages  of  fleshing  and  unhairing  In'  machinery;  Warm 
bath  for  limed  hides  380 

Necessity  of  carefully  and  thoroughly  scudding  the  grain;  Superiority 
of  hides  cured  by  Syracuse  coarse  salt;  Use  of  borax  for  preserving 
hides;  Sweated  hides      .       .       .  381 

Necessity  of  keeping  a  ledger  account  of  each  lot  of  hides  put  through 
the  tannery;  Suspension  of  the  hides  in  rockers;  Re-hanging  the  hides 
in  the  handlers;  Liquors  supplied  to  the  rockers  382 


XXII 


CONTENTS. 


PAGE 

Liquor  in  the  handlers ;  Lay-away  vats  ;  Schedule  of  the  time  and 
strength  of  liquor  employed  in  each  layer  383 

Liquor  used  for  the  various  layers;  Handling  the  pack  of  hides;  Laying 
away  light  hides  384 

Splitting  the  hides  and  treatment  of  the  sides;  Drying  and  the  best  tem- 
perature for  this  process  ..........  385 

Percentage  of  rough  leather  from  various  grades  of  hides;  Treatment  of 
hides  for  sumac  leather;  Rolling  machine  for  sole  leather    .       .       .  386 

Cut  soles  387 

Cut  sole  factory  .  388 

Revolution  in  the  trade  in  sole  leather  389 

CHAPTER  XXV. 

Harness  and  Belting  Leather. 

Hides  used  for  this  variety  of  leather;  Treatment  of  harness  hides  .       .  390 
Effect  of  too  concentrated  solutions  of  tannins  for  skins  and  lighter 
hides;  Belting  for  lighter  purposes  ........  391 

Chrome  tannage  for  harness  and  belting  leather;  Quick  tanning  process; 

Currying  harness  leather  392 

Currier's  skirting;  German  harness  leather  395 

Preparation  of  vache  leather     .........  397 

Drum  tannage    ............  399 

Indian  harness  leather;  Sketch  of  the  system  by  Walter  G.  McMillan  .  400 
The  system  of  tannage  used  in  the  Cawnpur  factory;  Analysis  of  water; 
Hides  used  ;   Tanning  material  employed  ;   Experiments  with  Sal 

(Shorea  Robusta)  401 

Sizes  and  weights  of  material  employed;  Mode  of  conducting  the  tan- 
ning process    ............  402 

Currying  403 

Tests  of  new  leathers;  Points  indicated  by  the  experiments    .       .       .  404 
Machine  belt  leather  greased  with  tallow  .......  405 

Currying  the  tallowed  leather    .........  406 

Currying  strap  butts  for  mill  band  and  engine  belts  407 

To  remove  grease  from  leather  belting,  etc  408 

Wet  stretching  machine  for  belt  leather,  built  by  the  Vaughn  Machine 
Co  409 

CHAPTER  XXVI. 

Danish  Leather. 

Definition  of  Danish  leather;  Nature  of  leather  obtained  by  willow  tan- 
nage; Use  of  glycerine  for  softening  purposes       .....  412 


CONTENTS. 


xxiii 


CHAPTER  XXVII. 

Russet  Leather. 


Material  for  russet  leather;  Uses  of  russet  leather  .  .  .  .  .414 
Preparation  of  russet  leather;  Proper  way  to  split  shoe  leather  .  .  4-15 
Splitting  card  and  strap  leather;  Light  color  on  the  leather;  Printing  the 

leather  416 

Dyeing  the  leather  417 


CHAPTER  XXVIII. 

Grain  and  Split  Leather. — Satin  Oil  Finish  ;  Oil  Grain  ;  Plow 
Grain  ;  Glove  Grain  ;  Imitation  Goat  or  Pebble  Grain  ;  Imita- 
tion Kangaroo  ;  Imitation  Seal  ;  Imitation  Hog  ;  Wax  Crimping 
Splits  ;  Flesh  Splits  ;  Doxgola,  Buffed  Leather,  and  Flexible 
Splits,  with  Stuffings,  Pastes,  Blacks,  Finishes,  etc. 


Qualities  in  upper  leather  looked  for  by  buyers;  English  crown  leather 

as  an  illustration  of  how  nicely  the  grain  is  broken  by  agitation.       .  418 
Bark  used  for  the  tannage  for  the  varieties  of  leather  under  considera- 
tion; Hides  used;  Soaking  the  hides      .  41it 

Splitting  and  fleshing;  Liming;  Unhairing;  Bating  .....  420 
Short-hairing  and  washing;  Treatment  in  the  handlers;  Skiving,  stoning 

and  splitting;  Running  in  a  pin  wheel  421 

Milling;  Scouring;  Drying  yard  of  an  upper  leather  tannery;  Stuffing; 

Various  kinds  of  stuffing  for  different  leathers  422 

Striking  out  the  sides;  Staining  and  blacking  424 

Finishing  bright  glove  grain,  imitation  of  goat  and  pebble  grain  and 
kangaroo  chrome  tannage;  Crimping  splits  ......  425 

Gum  tragacanth  finish  426 

Paste  for  upper  splits  and  calfskins;  Blacking  for  splits;  Paste  for  wax 

stock;  Imitation  seal  and  hog  427 

Plow  grain   428 

Flesh  splits;  Stuffing  for  flesh  splits  429 

Finishing  coat  for  flesh  splits;  Finishing  oil  grain  ;  Bright  finish  for 

glove  grain;  Blue  black  color  430 

Finishing  satin  oil  leather;  Imitation  of  goat  or  pebble  grain  finish; 
Kangaroo  finish;  Very  bright  pebble  grain  finish  .....  431 

Blue  black  liquor  for  finishing;  Buffed  leather  432 

Flexible  splits  433 

Degras  435 


xxiv 


CONTENTS. 


CHAPTER  XXIX. 

Enameled  Leather,  Patent  Leather,  Furniture  or  Upholstering 
Leather,  Regalia  Leather. 

PAGE 


Hides  used  for  the  production  of  enameled  and  patent  leather;  Soaking, 

unhairing,  fleshing  and  liming;  Bating  430 

Further  treatment  of  the  hides  437 

Tanning  vats  in  patent  leather  factory;  Materials  employed  for  tanning.  438 

Splitting  the  hides;  Re-tanning  the  hides  and  splits  439 

Scouring  the  hides  and  splits;  Stuffing  which  has  been  found  to  be  sat- 
isfactory  440 

Frame  for  stretching  leather  invented  by  Chas.  P.  Oliver  and  Theodore 

P.  Howell  *    .       .       .  .441 

Softening  the  hides  and  splits;  Patching;  Sorting;  Grades  of  hand-buffed 

hides  443 

Grades  of  machine-buffed  hides  ;  Kinds  of  leather  the  splits  make  ; 
Classes  of  buffing  selected  for  japanning;  Hide  frames  and  their  con- 
struction; Black  enameled  top  leather  such  as  in  use  for  buggy  and 
carriage  tops;  Preparation  of  daub  of  raw  linseed  oil    .       .       .       .  444 

Application  of  the  daub  ;  Drying  oven  in  patent  leather  factory  ;  The 
slicker  coat;  Preparation  of  enameled  varnish      .....  440> 

Final  finishing  coat;  Smooth  finished  patent  leather       ....  447 

Preparation  of  the  black  vsrnish;  Application  of  the  varnish;  Final  coat 
of  varnish       ............  448 

Preparation  of  finishing  varnish  ;  Plain  black  buffings  ;  Furnishing  or 
upholstering  leather       ..........  449 

Regalia  leather;  Notes;  Management  of  the  finishing  room;  Naphtha 
and  turpentine  as  reducing  agents  ........  450 

Brushes  and  other  tools  ;  A  good  way  to  open  enameled  and  patent 
leather  which  is  stuck  together;  Preserving  the  gloss  of  patent  leather; 
Renewing  the  surface  of  japanned  leather     ......  461 

Preparing  the  cut  surface  of  split  leather  for  manufacturing  japanned  or 
enameled  leather;  Stephen  J.  Patterson's  method  for  forming  an 
artificial  grain  on  the  hide  after  it  has  been  buffed  or  split  .       .       .  45l! 
Japanned  leather  in  imitation  of  alligator  skin.       .....  453 

Linseed  oil;  Constituents  of  linseed  ........  454 

Cold  drawn  oil;  Ordinary  linseed  oil;  Yield  of  oil  by  extraction ;  Prop- 
erties of  linseed  oil  ..........  455 

Constitution  of  linseed  oil;  Reactions  of  linseed  oil  with  acids       .       .  45G 
Detection  of  adulterations;  Uses  of  linseed  oil  .       .       .       .       .       .  457 

Commercial  forms  of  linseed  oil;  Selection  of  the  oil  to  be  boiled;  Chem- 
ical changes  induced  in  linseed  oil  by  exposure  to  the  air  ;  Metallic 
oxides  used  in  boiling  linseed  oil   .......  458 


CONTENTS. 


xxv 


PAGE 

Reasons  for  boiling  linseed  oil  ;  Test  for  the  drying  qualities  of  boiled 
oil;  The  philosophy  of  the  process  of  driving  off  by  heat  the  mucilage 
from  the  seed  4oi» 


CHAPTER  XXX. 

Horse  Leather. 
Origin  of  the  manufacture  of  horse  hides  for  foot  wear;  Foundation  for 


a  good  finished  product;  Manipulation  of  the  hides     ....  401 

Tanning  of  the  hides;  Splitting;  Cordovan  402 

Manipulation  of  the  hides  403 

Wax  finish  on  chrome-tanned  horse  hide  butts  (cordovan);  Horse  hides 

for  enamel      ............  464 

Horse  hides  for  plain  enamel;  Horse  hides  for  memel      ....  405 


CHAPTER  XXXI. 
Alligator  Leather. 


Alligator  hunting  industry  in  Louisiana;  Scarcity  of  alligators       .       .  400 
Present  chief  source  of  alligator  skins;  Average  price  of  alligator  skins.  467 
Manipulation  of  the  skins  previous  to  tanning;  Tanning;  Treatment 
after  tanning  46S 


CHAPTER  XXXII. 

Russia  Cai.f. 


Process  of  making  colored  or  Russia  calf;  Soaking  ;  Milling;  Constitu- 
tion of  the  limes  470 

Fleshing  and  fine-hairing;  Tanning;  Division  of  tan-room;  Strength  of 
the  liquors;  Manipulation  in  tanning  471 

Strengthening  and  clearing  the  tanned  stock;  Fat  liquoring  .       .       .  472 

Coloring;  Application  of  egg;  Finishing  manipulations;  Another  process 
for  coloring     ............  473 

Composition  of  colors  474 


xxvi 


CONTENTS. 


CHAPTER  XXXIII. 

The  Manufacture  of  Russia  Leather  —  Russian  Method  of  Pre- 
paring and  Applying  the  Mordant  and  Dye — Manufac- 
ture of  Birch  On.. 

PAGE 


Russia  leather  as  made  in  Russia;  Characteristics  and  uses  of  Russia 
leather     .............  475 

vSource  of  the  peculiar  odor  of  Russia  leather;  Locations  of  leather  man- 
ufactories in  Russia;  Process  of  making  Russia  leather  in  Russia       .  47t> 
Other  processes  of  tanning.       .........  477 

Peculiar  Russian  process  for  freeing  the  hides  from  lime;  Manufacture 

of  Russia  leather  in  Austria;  Preparation  of  birch  oil  by  the  Russians.  478 
Preparation  of  birch  tar  or  oil  in  America;  Different  claims  made  con- 
cerning the  manufacture  of  Russia  leather    ......  479 

Cause  of  the  red  color  of  Russia  leather  ;  Method  of  manufacturing 

Russia  leather  in  the  United  States  480 

Dyeing  the  leather;  Treatment  of  the  leather  after  dyeing  .  .  .  481 
Preparation  of  the  mordant  used  in  Russia  ;  Coloring  matter  used  in 

Russia;  Mode  of  dyeing  482 

Giving  a  brilliant  appearance  to  red  Russia  leather;  Graining.       .       .  483 
Black  colored  Russia  leather;  Manufacture  of  birch  oil   .       .       .       .  484 

Fischerstroem's  method  of  manufacturing  birch  oil  ;  Grouvelle  and 
Duval-Duval's  process     ..........  485 

Payen's  apparatus  for  repeating  distillation  in  order  to  obtain  an  oil  less 
colored;  Products  obtained  by  the  distillation  of  one  hundred  parts; 
Birch  oil  and  leather;  Manner  of  obtaining  birch  oil    .       .       .       .  486 

Preparation  of  birch  tar  and  birch  tar  oil  .......  487 

Russia  odor  to  calf  leather;  Birch  tar  and  pine  tar — their  differentiation.  488 


CHAPTER  XXXIV. 

Weighing  of  Leather. 
No  notable  advances  made  in  the  art  of  weighting  leather;  Indication  of 


the  presence  of  sugar;  Analysis  of  a  sample  of  sole  leather  .       .       .  489 

CHAPTER  XXXV. 
Tanning  and  Dyeing  Furs  and  Hair-Skins. 

Tanning  calf  skins   491 

For  tanning  furs,  peltries  and  deer  skins  .......  493 

In  the  process  of  cold  tan;  Dyeing  fur  skins   494 


CONTENTS. 


xxvii 


PAGE 

Latest  developments  in  the  dyeing  of  fur  skins;  Experiments  with  ursol 
colors  495 

Methods  for  "killing  the  skin  ;"  Preparation  of  a  degreasing  liquid; 
Mordanting  the  skins     ........       .       .  496 

Representative  example  of  the  method  of  dyeing;  Dyeing  rabbit  skins 
golden  brown;  Dyeing  goat  skins  and  Thibet  or  wild  goat  skins .       .  497 

Light  brown  for  long-haired  musk-ox;  Dyeing  imitation  of  seal-skin  in 
clipped  musk-ox;  Imitation  nutria  in  clipped  rabbit;  Intense  black  for 
angora  goat  or  other  similar  skins ........  498 

Directions  for  producing  a  blue-black  tinge;  Peculiar  advantage  in  dye- 
ing with  ursol  colors;  Appliances  required  for  practical  dyeing  with 
ursol  colors      ............  499 

Improvements  relating  to  the  manufacture  of  artificial  fur,  beaver  and 
nutria;  Weights  and  measures  used  in  this  chapter      ....  500 

CHAPTER  XXXVI. 

Tawing  Lamb  and  Kid  Skins  for  Glove  Leather,  Dyeing,  etc. 

Preparation  of  the  material  for  gloves;  Soaking;  Washing;  Liming.  .  501 
Unhairing;  Fleshing;  Drenching;  Tawing;  Softening  and  the  mill  used 

for  this  purpose       ...........  50- 

Ripening  and  selecting  the  skins  for  coloring;  Coloring  the  skins;  Black 

on  glove  skins  503 

CHAPTER  XXXVII. 

To  Put  a  Gi.oss  on  Black  Leather. 

Various  solutions  for  putting  a  handsome  and  brilliant  gloss  on  black 
leather  and  the  methods  for  manufacturing  them.       ....  505 

CHAPTER  XXXVIII. 

Sheep  Leathers. 

Importance  of  the  sheep-skin  industry;  Uses  for  which  sheep-skins  are 
suitable  507 

Unhairing  sheep-skins;  Removal  of  grease  from  raw  sheep-skins    .       .  508 

Bating  the  skins;  Compounds  used  as  substitutes  for  hen  or  pigeon  ex- 
crement; The  Vaughn  Machine  Co.'s  shaving  and  skiving  machine 
for  sheep-skins  509 

Imitation  chamois  leather  510 


xxvm 


CONTENTS. 


PAGE 

White  leather   .  .  511 

Cape  sheep;  Lining,  binders  and  skivers;  Exterior  view  of  a  sheep-skin 
tannery     .............  512 

Tanning  vats  in  a  sheep-skin  tannery;  Interior  view  of  a  drying  loft  in  a 
sheep-skin  tannery;  Finishing  room  in  a  sheep-skin  tannery;  Dressing 
sheep-skin  fleshers  for  glove  bindings,  etc.;  Richard  Hart's  process    .  513 

Manasse's  method  for  tawing  sheep-skins   .  519 

Hibbard's  process  for  preparing  and  tanning  sheep-skins  ;  Unhairing 
composition  ;  Tanning  composition  ;  Hesthal's  process  for  dressing 

sheep-skins,  etc.  520 

Coloring  for  five  dozen  sheep-skins;  Blue-reddish;  Blue-bluish       .       .  522 
Cochineal;  Lemon  yellow;  Grass  green     .......  523 

Claret  or  maroon;  Pink      ..........  524 

Solferino;  Dyeing  bark-tanned  sheep-skins  intense  dull  black       .       .  525 

CHAPTER  XXXIX. 

Electric  and  other  Rapid  Tannage  Systems. 

The  Groth  system  of  rapid  tannage;  E,  Worms's  process;  Various  pro- 
cesses for  electric  tannage      .........  52G 

M.  C.  Dizer  &  Co.'s  experiments  in  rapid  tannage;  Other  processes  of 
quick  tannage;  S.  Kas  on  rapid  tannage;  Revolution  in  quick  tan- 
ning processes.   .       .  527 

Future  possibilities  of  quick-tanning  processes.       .....  528 

Value  and  economy  of  quick-tanning  processes;  Prejudice  of  tanners 
against  testing  the  merits  of  new  processes    ......  529 

Arrangement  of  modern  tanning  and  currying  shops       ....  530 

Necessity  of  thoroughly  cleansing  the  hides  or  skins      ....  531 

CHAPTER  XL. 

Bleaching  Leather  ;  Bluing  White  Leather  ;  Bleaching  Skins 
with  the  Hair  on. 

Bleaching  leather;  Former  process  of  bleaching  with  sulphurous  acid  .  532 

Bleaching  chamber  533 

Bleaching  with  solution  of  sulphurous  acid;  Apparatus  for  the  produc- 
tion of  the  acid  534 

Bleaching  with  sodium  peroxide;  Bleaching  with  hydrogen  peroxide    .  535 
Bleaching  with  aluminium  hypochlorite  or  magnesium  hypochlorite; 
Bleaching  chamois  leather;  Bluing  white  leather  ....  r»3f> 


CONTENTS. 


XXIX 


PAfiE 

Bleaching  heavy  leather;  Recipe  for  bleaching  bull's,  stag's  or  russet 


harness  leather;  Recipe  for  bleaching  leather       .....  537 

Imparting  a  light  color  to  leather  538 

Agents  used  for  toning  clown;  Proper  method  of  using  diluted  sulphuric 

acid  539 

To  bleach  skins  with  the  hair  on;  Methods  for  bleaching  lamb  or  goat 

skins  intended  for  rugs,  lap-robes,  etc  540 

Use  of  peroxide  of  hydrogen  and  of  peroxide  of  sodium  ....  541 


CHAPTER  XLI. 

Lace  Leather. 


Treatment  of  dry  Calcutta  hides  542 

Manipulation  in  the  tub  wheel;  Stretching       ......  543 

Stuffing;  Softening  544 

Finishing;  Mode  of  imparting  a  golden  yellow  color  to  lace  leather; 

Junior's  method  of  manufacturing  lace  leather  .....  545 
Quick  tanning  process  for  lace  and  whip  leather ;  Barteubach  and 

Richter's  process     ...........  540 

Loescher's  method  for  manufacturing  lace  leather;  Coupe's  stretching 

machine  547 

Tidd's  softening  machine  ..........  549 


CHAPTER  XLII. 

The  Dyeing  of  Leather. 


Hints  for  obtaining  a  uniformly  colored  lot  with  coal  tar  colors;  Special 
adaptability  of  aniline  colors  for  dyeing  leather    .....  553 

Manner  of  dyeing  with  aniline  colors;  Mordants  and  their  division  into 
three  groups;  The  most  important  bases  and  the  most  important  salts 
used  in  leather  dyeing  554 

Soaps;  Assorting  the  leather  for  dyeing;  Dark  brown      ....  555 

Light  brown;  Olive  brown;  Cutch  brown;  Chestnut  brown;  Chocolate 
brown;  Red;  Alizarine  red;  Scarlet.  556 

Ordinary  red;  Dark  green;  Light  olive  green;  Picric  green;  Lemon 
yellow;  Barberry  yellow;  Orange;  Chrome  yellow;  Temperature  in 
leather  dyeing  557 

The  English  and  Continental  methods  of  dyeing  leather;  Advantage  in 
paddle  dyeing;  Durability  of  wood  dyes;  Application  of  alizarine 
colors  to  chrome-tanned  leather     ........  558 


XXX 


CONTENTS. 


PAGE 


Indigo  carmine;  Young  fustic;  Extract  of  peach  wood  or  red  wood; 
Creme  of  logwood  559 

Clearing  skins  preparatory  to  dyeing;  Waterproof  colors;  Dimitry's  pro- 
cess  560 

Mordants;  Minerals  used  as  mordants;  Necessity  of  removing  an  excess 
of  mordanting  solution;  Precautions  in  dyeing  with  aniline  colors      .  561 

Precautions  regarding  cleanliness  of  vessels,  etc.;  Manner  of  facilitating 
evenness  of  color;  "Tanners'  preparation"  for  obtaining  uniform 
colored  leather.       ...........  562 

Bleeding  or  smutting  off  of  colors     ........  563 

The  practical  dyeing  of  leather  with  aniline  colors;  Samples  dyed  in  a 
practical  way;  Sample  No.  I.,  Russia  calf — combination  tannage; 
Sample  No.  II.,  Russia  calf — combination  tannage      ....  564 

Sample  No.  III.,  Glove  sheep  leather — Atteaux  O.  B.  mineral  tan; 
Sample  No.  IV.,  Sheep-skin — sumac  tannage  ;  Sample  No.  V., — 
Atteaux  O.  B.  mineral  tan;  Sample  No.  VI., — Atteaux  O.  B.  mineral 
tan;  Sample  No.  VII.,  India  tanned  goat;  Sample  No.  VIII.,  Sheep- 
skin ..............  565 

Sample  No.  IX.,  Dark  green  India  tanned  goat  skin;  Sample  No.  X., 
Pickle  sheep-skin  tannage — two-bath  chrome;  Sample  No.  XL,  For 
I  dozen  sheep  skins — hemlock  tannage;  Sample  No.  XII.,  Goat  skin 
— Atteaux  O.  B.  mineral  tan;  List  of  aniline  and  alizarine  colors  that 
work  to  advantage  on  leather.       .       .       .       .       .       .       .       .  566 

Formula  for  obtaining  the  correct  ox-blood  shade  on  combination  tan 
or  straight  gambier  tanned  calf  skins     .       .       .       .       .  .  567 

Sample  of  patent  phosphine  leather  ........  568 

Sample  of  quebracho-tanned  leather;  Summary  of  the  advantages  of 
using  quebracho;  Calf  leather  dyeing     .......  569 

List  of  leather  dyes  570 

The  dyeing  of  leather  for  shoes;  Process  for  preparing  tanned  calf  skins 
for  dyeing       .       .   ■   .       .       .  571 

Dyeing  calf  skins  for  shoe  work;  Colors  for  any  shade  of  brown      .       .  572 

Varieties  of  colored  leather  used  for  shoes;  Directions  for  obtaining  cor- 
rect ox-blood  shade  on  one  dozen  chronie-tauued  calf  skins.       .       .  573 

Methods  of  dyeing  leather  used  in  Germany;  Preparing  the  dye  bath    .  574 

On  what  the  depth  of  a  certain  color  is  dependent ;  Preparation  of  a 
mordant  of  tin-salt  .:....  575 

Difficulty  of  always  obtaining  a  definite  tone  of  color;  Use  of  solutions 
of  coloring  matters  of  an  exactly  determined  concentration;  Theory 
of  solutions  '  576 

Best  method  of  effecting  dilution ;  Preparation  of  a  sample  scale  of 
leather  577 

Working  with  ready-made  dye-stuffs;  Toning  fluids;  Mode  of  action  of 
toning  fluids    ............  578 

Preparation  of  toning  fluids       .........  579 


CONTENTS. 


xxxi 


PAGE 


The  color  mixtures;  Directions  regarding  the  respective  proportions  for 

the  different  kinds  of  leather;  Genuine  Russia  leather  .       .       .       .  580 
Morocco  leather;  Cordovan  leather;  Chamois  leather;  Tawed  leather     .  581 
The  proper  selection  of  dye-stuffs;  The  most  important  dyes  of  the 
group  of  the  aniline  colors  ;  Colors  for  pure  colors  without  toning; 
Coloring  matters  for  colors  formed  by  mixing  two  coloring  matters   .  583 
Blended  colors;  Use  of  aniline  colors  besides  wood  colors;  Preparation  of 

the  leather  for  dyeing  584 

Sorting;  Principal  point  to  be  observed  in  sorting  morocco  and  cordovan 
leather;  The  most  difficult  task  in  sorting  tawed  leather;  Separation 
of  the  skins  into  several  classes     ........  585 

Washing  the  skins      ...........  586 

The  object  of  washing;  Mechanical  pressure  in  washing;  Treading  the 

skins  '  587 

The  washing  machine.  588 

Time  required  for  washing  591 

Rules  in  reference  to  washing  leather       .......  592 

Quality  of  the  water;  Importance  of  the  chemical  constitution  of  the 

water   593 

Forster's  sandstone  filter  for  filtering  turbid  water  .....  594 

Nourishing  .............  595 

Nourishment  of  fine  glace"  leather;  Operation  of  nourishing   .       .       .  596 
Preservation  of  yoke  of  egg;  Lanolin.       .......  597 

Dyeing  tawed  leather  (glace  leather);  Dipping  process    ....  598 

Dipping  apparatus   599 

Manner  of  operating  the  apparatus    ........  600 

Dyeing  upon  the  board;  Utensils  required;  The  dyeing  table  or  board; 

Arrangement  of  the  fluids  required  in  dyeing;  The  operation  of  dyeing.  601 
Avoidance  of  the  formation  of  stains  ;  Action  of  the  mordant  with  the 

use  of  vegetable  dye-stuffs;  Working  with  aniline  colors      .       .       .  602 
Dyes  and  toning  fluids;  Proper  use  of  aniline  colors  and  of  indigo  car- 
mine 603 

Aniline  colors  for  colors  of  a  pure  tone;  Aniline  colors  for  dyeing  glace" 
leather  for  fancy  goods  ;  Directions  for  the  production  of  blended 
colors  upon  glace  leather;  Light  ochre  yellow  and  maize  yellow       .  004 
Dark  gold  color  to  umber;  Wood  brown  to  mahogany  color;  Reddish 
brown  to  Venetian  red;  Brownish  red  (Pompeian  red);  Pure  Havana 
brown;  Sienna  brown ;  Dark  bister  brown      ......  605 

Olive;  Red  brown  to  dark  brown;  Green  brown  to  dark  brown;  Lac 
brown  and  dark  brown;  Sepia  brown;  Iron  violet;  Gray  blue  (dark 

pigeon  gray)  606 

Slate  gray;  Iron  or  steel  gray;  Light  ash  gray;  Toning  fluids  for  the  dif- 
ferent broken  colors       ..........  607 

Mixed  colors;  Definition  of  the  term;  Dyeing  with  mineral  colors  .  .  608 
Dyeing  leather  black  609 


xxxii 


CONTENTS. 


PAGE 

Dyeing  with  tannin  and  iron  salts;  Dyeing  with  logwood  and  potassium 

chromate  610 

Dyeing  with  tannin  and  logwood       .       .       .       .       .       .       .  .Gil 

Deep  black  nigrosin  color;  Blue  black  nigrosin  color;  Glazing  and  gloss- 
ing of  leather;  Glazing;  Preparation  of  the  glazing  fluid       .       .       .  612 

Application  of  the  glazing  fluid.  613 

Glossing;  Preparation  of  a  glossing  mass;  Glossing  rolls  .  .  .  .  614 
Use  of  vaseline  and  by-products  of  the  tar  industry  for  rendering  the 

leather  pliable  and  for  glossing;  Glazing  rolls  .....  G15 
Dyeing  rabbit  skins  black  .  616 

APPENDIX. 

Method  of  coloring  chrome-tanned  leather;  Win.  M.  Norris'  patent  .  G17 
Art  of  tawing  hides  or  skins;  Wm.  M.  Norris'  patent       ....  618 

Borax  622 

Anthrax  629 

Degras  630 

American  degras  from  wool  waste  631 

The  per  cent,  of  water  in  degras       .  632 

Tanning  matters  and  their  determination  .......  633 

Electric  transmission  of  power  636 

To  dress  strap,  pocket  book,  bag,  case  and  welt  leather  and  flexible 

splits  637 

List  of  patents  relating  to  the  manufacture  of  leather,  issued  by  the  gov- 
ernment of  the  United  States  of  America,  from  January  i,  1884,  to 

August  31,  1897  639 

Index   ■  655 


THE  MANUFACTURE  OF  LEATHER. 


CHAPTER  I. 

WATER  AND  PUMPS. 

Tanneries  and  currying  shops  are  not,  in  the  United  States, 
located,  as  a  rule,  upon  rivers  and  streams,  as  they  are  in  many 
parts  of  Europe.  There  are  advantages  in  being  located  upon 
rivers  and  streams,  in  having  at  nearly  all  times  a  uniformity  in 
the  hardness  or  softness  of  the  water ;  but  there  are  also  disad- 
vantages in  the  great  variations  of  its  temperature.  The  idea 
in  the  United  States  is  to  have  the  tannery  or  currying  shop 
located  upon  a  railroad  switch,  so  as  to  have  easy  and  cheap 
communication  with  all  parts  of  the  country,  and  hence  the 
softness  or  hardness  of  the  water  is  made  a  minor  detail.  If 
hard,  it  takes  more  tan  bark  or  extract  to  do  the  tanning  than 
if  it  were  soft,  and  more  dyeing  materials  to  do  the  coloring. 

However,  water  occupies  an  important  position  in  tanning, 
it  being  employed,  on  the  one  hand,  for  washing,  cleansing, 
and  preparing  the  raw  hides,  and  on  the  other,  as  a  solvent  for 
all  the  tanning  materials  and  as  a  diluent  for  all  the  coloring 
and  dyeing  materials  used. 

We  shall  here  briefly  discuss  the  most  important  admixtures 
of  water,  and  their  influence  in  tanning. 

All  naturally  occurring  water  contains  smaller  or  greater 
quantities  of  alkaline  and  earthy  alkaline  salts,  and  carbonic 
acid  in  solution.  There  is  no  entirely  pure  well  or  river  water, 
i.  e.,  free  from  all  admixtures.  By  leaving  out  of  consideration 
the  small  quantity  of  ammonium  nitrite,  organic  substances, 

(O 


2 


THE  MANUFACTURE  OF  LEATHER. 


etc.,  held  in  solution  by  rain  water,  the  latter  might  be  consid- 
ered chemically  pure  water. 

Water  is  distinguished  as  hard  and  soft,  according  to  the 
quantity  of  earthy  alkaline  salts  it  contains,  the  amount  of  min- 
eral substances  varying  from  I  milligrm.  to  I  grm.  per  litre. 
The  principal  admixtures  occurring  in  water  are,  as  mentioned 
above,  the  alkalies,  such  as  potassium,  sodium,  alkaline  earths, 
lime,  and  magnesia ;  the  oxides  of  a  few  heavy  metals  in  com- 
bination with  ordinary  mineral  acids,  sulphuric,  nitric,  phos- 
phoric, carbonic,  and  hydrochloric  acids.  The  gases  held  in 
solution  are  chiefly  carbonic  acid  and  atmospheric  air,  sulphide 
of  hydrogen  occurring  but  seldom. 

The  admixtures  of  spring  and  well  water  consist  principally 
of  the  constituents  of  the  layers  of  earth  through  which  it  per- 
colates. Those,  for  instance,  contained  in  the  waters  flowing 
through  the  dolomitic  stratification  may  be  considered  as  pure 
solutions  of  the  dolomitic  rock,  consisting  as  they  do  of  calcium 
carbonate,  magnesium  carbonate,  and  silicic  acid,  the  quantity 
of  all  other  constituents  being  so  small  as  to  make  it  almost 
impossible  to  determine  them  by  quantitative  analysis.  The 
waters  percolating  through  the  basalt  and  the  new  red  sand- 
stone contain  principally  calcium  carbonate,  magnesium  car- 
bonate, silicic  acid,  considerable  quantities  of  free  carbonic 
acid  and  small  quantities  of  common  salt,  calcium  sulphate,  and 
sodium  carbonate.  The  total  dry  residue  of  waters  coming 
from  the  lias  formation  varies  between  268  and  516  milligrms., 
the  principal  constituents  being  in  this  case  also  calcium  car- 
bonate, 200  to  400  milligrms.  per  litre,  magnesium  carbonate 
(varying  from  30  to  90  milligrms.  per  litre),  sodium  carbonate, 
free  carbonic  acid,  etc. 

Besides  these  natural  constituents,  spring  and  well  water,  but 
especially  the  latter  when  in  large  cities  or  in  the  neighborhood 
of  dumping  places  for  all  kinds  of  offal,  the  soluble  substances 
of  which  percolate  through  the  soil,  contain  frequently  in  solu- 
tion organic  products  of  decomposition  of  organized  bodies 
such  as  bacteria,  fungi,  alkaline  nitrates,  especially  ammonia, 


WATER  AND  PUMPS. 


3 


and  alkaline  salts.  Though  such  water,  for  hygienic  reasons, 
is  generally  unfit  for  drinking  purposes,  it  may  be  put  to  tech- 
nical use. 

In  determining  the  qualities  of  water  for  tanning  purposes, 
two  points,  as  mentioned,  must  be  taken  into  consideration, 
viz.,  first,  the  behavior  of  the  water  when  used  as  a  solvent  for 
the  tanning  materials,  and  second,  whether  it  is  adapted  for 
preparing  the  hides  for  tanning.  If  the  water  is  to  be  used  for 
dissolving  or  extracting  tanning  materials  containing  tannic 
acid,  the  earthy  alkalies,  lime  and  magnesia  combinations,  exert 
a  decidedly  injurious  effect,  as,  by  forming  insoluble  combina- 
tions with  the  tannic  acid,  they  render  a  part  of  the  tanning 
material  ineffective.  If  the  water  is  to  be  used  for  soaking, 
cleansing,  and  washing  the  hides,  mineral  admixtures  may  exert 
a  favorable  influence.  In  speaking  of  the  chemical  properties 
of  the  skin  tissue  and  the  coriin,  it  will  be  shown  that  some  of 
the  alkaline  salts  exert  a  dissolving  influence  upon  the  intercel- 
lular substances  or  coriin,  the  effect  of  small  quantities  of  alka- 
lies being  an  increased  solution  of  coriin  in  acids.  From  this 
we  may  draw  the  conclusion  that  hard  water  promotes  the 
soaking  of  dried  hides,  but  that  a  part  of  the  coriin  is  with- 
drawn from  the  skin  tissue  if  the  hide  is  too  long  subjected  to 
the  action  of  the  water.* 

Hides  intended  for  sole  leather  are  swelled  or  "plumped"  in 
order  to  cause  them  to  be  better  adapted  to  the  absorption  of 
the  tanning  material.    In  case  the  natural  swelling  is  not  suffi- 

*  Eitner  (see  Der  Gerber,  1877,  No.  178,  and  Dingl.  Polyt.  Journ.,  ccxxiv,  524) 
has  made  experiments  as  regards  the  effect  of  different  inorganic  constituents  of 
water  upon  the  depilated  skin,  using  various  solutions  of  alkaline,  calcium,  and  mag- 
nesium salts  in  distilled  water.  He  found  that  water  containing  only  calcium  chlor- 
ide and  magnesium  chloride  had  almost  no  swelling  effect,  and  distilled  water 
scarcely  any,  it  being  further  remarked  that  carbonic  acid,  and  consequently  water 
containing  bicarbonates,  exerted  a  swelling  effect  upon  the  hide.  Alkaline  chlorides 
and  alkaline  earths,  such  as  magnesium  chloride,  potassium  and  sodium  chlorides, 
have  no  swelling  effect  whatever,  even  nullifying  it  partly.  Calcium  and  magnesium 
sulphates  proved  the  best  swelling  materials  for  hides,  this  explaining  the  advantage- 
ous effect  produced  in  swelling  by  a  careful  addition  of  sulphuric  acid  to  water  con- 
taining much  bicarbonate. 


4 


THE  MANUFACTURE  OF  LEATHER. 


cient,  it  is  assisted  by  the  use  of  inorganic  as  well  as  organic 
acids.  This  swelling  process  is  accelerated,  and  the  falling  back 
of  the  hides  into  their  previous  state  prevented  by  the  use  of 
hard  water. 

Soft  water  is  preferred  for  the  manufacture  of  upper  leather, 
since  the  hides  must  not  be  swelled  so  much  as  those  for  sole 
leather,  as  otherwise  the  smooth  cut  would  be  injured. 

The  temperature  of  the  water  used  for  preparing  the  hides 
must  also  be  taken  into  consideration.  Generally  speaking,  the 
water  should  be  as  cold  as  possible  for  the  manufacture  of  sole 
leather  to  prevent  the  skin  fibre  from  being  softened  too  much. 

It  is  also  of  importance  that  the  water  should  not  be  exposed 
to  too  great  variations  in  temperature  in  summer  and  winter; 
46  to  500  F.  may  be  designated  as  the  most  favorable  temper- 
ature. Spring  water  coming  from  deeper  strata  of  the  soil,  and 
possessing  consequently  a  more  even  temperature,  is  to  be  pre- 
ferred to  river  water. 

As  regards  the  chemical  examination  of  water,  we  refer  the 
reader  to  the  following 

METHODS  FOR  DETERMINING  THE  CONSTITUENTS  OF  WATER. 

We  cannot  enter  upon  a  description  of  the  different  qualita- 
tive and  quantitative  methods  of  determining  the  constituents 
of  water ;  but  will  only  briefly  describe  a  few  examinations 
of  importance  in  tanning,  and  those  who  may  desire  a  full 
description  of  the  methods  and  apparatus  employed,  are  re- 
ferred to  the  treatises  of  Wanklyn  and  Frankland  on  Water 
Analysis. 

The  qualitative  examinations  of  water  as  to  its  admixtures  of 
lime,  magnesia,  alkalies,  chlorine  combinations,  sulphuric  and 
carbonic  acids,  the  larger  or  smaller  quantity  of  which  gener- 
ally determines  its  character,  can  be  executed  in  the  following 
manner : 

1.  The  chlorine  combinations  are  shown  by  the  formation  of 
a  white  precipitate  when  treated  with  nitrate  of  silver  in  nitrate 
solution. 


WATER  AND  PUMPS. 


5 


2.  Sulphuric  acid  and  sulphates  are  recognized  by  the  for- 
mation of  a  white  precipitate  with  barium  chloride. 

3.  Carbonic  acid  is  present  when  the  addition  of  clear  lime- 
water  gives  a  white  precipitate. 

4.  The  presence  of  silicic  acid,  lime,  and  magnesia,  by  evap- 
orating to  dryness  with  an  addition  of  hydrochloric  acid  in  a 
platinum  dish  of  a  capacity  of  about  one  litre.  The  residue  is 
taken  up  with  hydrochloric  acid  and  water,  the  portion  remain- 
ing undissolved  being  silicic  acid.  The  lime  can  be  separated 
as  calcium  oxalate  from  the  filtrate  with  ammonium  oxalate. 
After  removing  the  calcium  oxalate  by  filtration  and  evapora- 
tion of  the  filtrate,  the  magnesia  is  precipitated  with  ammonium 
phosphate  as  ammonium  magnesium  phosphate. 

5.  Organic  substances  are  shown  by  adding  a  few  drops  of 
potassium  permanganate  and  some  pure  sulphuric  acid.  If 
organic  substances  are  present,  the  potassium  permanganate, 
added  drop  by  drop,  is  decolorized  until  all  the  organic  sub- 
stances are  completely  oxidized. 

6.  Determination  of  the  entire  residue.  One  litre  is  carefully 
evaporated  to  dryness,  requiring  from  twenty-four  to  twenty- 
six  hours,  in  a  platinum  dish,  the  weight  of  which  has  been 
previously  determined.  The  residue  is  dried  at  3 560  F.  until 
a  decrease  in  weight  no  longer  takes  place. 

7.  A  determination  of  hardness  with  alcoholic  soap  solution 
serves  in  most  cases  for  tanning  purposes  as  a  substitute  for  a 
quantitative  analysis.  We  give,  therefore,  a  short  description 
of  it. 

The  process  of  determining  the  hardness  of  water  by  a  soap 
solution  of  a  determined  percentage,  which  was  introduced  by 
Clark,  is  a  very  simple  one.  By  an  addition  of  soap  solution 
to  water  containing  too  much  lime  or  magnesia,  a  white  preci- 
pitate of  lime  or  magnesia  soap  insoluble  in  water  is  formed  as 
long  as  calcium  or  magnesium  salts  are  present.  When  an  ex- 
cess of  soap  solution  has  been  added,  the  end  of  the  reaction 
is  indicated  by  the  formation  of  lather  on  shaking  the  fluid. 

The  effective  value  of  the  soap  solution  is  determined  by 


6 


THE  MANUFACTURE  OF  LEATHER. 


testing  it  with  a  lime  solution  of  a  determined  percentage. 
Clark's  method  is,  according  to  Faisst  and  Knauss,  executed  in 
the  following  manner: — 

The  soap  solution  required  for  titration  is  obtained  by  dis- 
solving 30  grms.  of  dried  soda  soap  in  3  litres  of  alcohol  of  90 
per  cent.  The  turbid  solution  is  filtered  and  preserved  for  use. 
200  grms.  of  this  concentrated  solution  are  first  compounded 
with  150  grms.  of  water  (in  order  to  reduce  the  alcohol  to  the 
strength  of  560  Tralles,  which  has  been  proven  to  be  the  most 
suitable),  and  then  with  130  grms.  of  spirit  of  wine  of  560 
Tralles.  45  c.c.  of  the  solution  thus  obtained  are  required  for 
the  precipitation  of  12  milligrams,  of  lime  in  100  c.c.  of  water. 
The  exact  titre  of  this  solution  must  be  further  determined  and 
corrected  by  adding  concentrated  soap  solution,  or  alcohol  of 
560  Tralles,  so  that  12  milligrms.  of  lime  require  exactly  12 
milligrms.  of  soap  solution.  For  the  determination  of  the  con- 
centration of  the  soap  solution  a  neutral  solution  of  calcium 
chloride  is  used,  which  is  obtained  by  dissolving  0.214  grm.  of 
calcium  carbonate  in  hydrochloric  acid,  evaporating  the  solu- 
tion, and  dissolving  the  residue  to  1  litre.  100  c.c.  of  this 
solution  contain  12  milligrms.  of  calcium  oxide,  or  an  equiva- 
lent quantity  of  calcium  chloride.  With  this  solution  the  soap 
solution  is  tested,  and  the  latter  sufficiently  diluted,  so  that 
exactly  45  c.c.  are  required  to  produce,  when  brought  together 
with  100  c.c.  of  lime  solution,  and  shaken,  a  white  lather  re- 
maining for  about  five  minutes. 

The  process  of  determining  the  hardness  is  as  follows :  A 
distinction  is  made  between  "total  hardness"  and  "permanent 
hardness."  The  hardness  of  water  not  heated  is  called  "total 
hardness,"  and  the  hardness  produced  by  the  earthy  sulphates 
is  termed  "permanent  hardness,"  because  unaffected  by  ebulli- 
tion; the  term  "temporary"  or  "changeable  hardness,"  is 
also  frequently  used  to  denote  the  hardness  produced  by  the 
earthy  carbonates,  because  removable  by  ebullition. 

1.  Determination  of  Total  Hardness. — 100  c.c.  of  water  are 
measured  with  a  pipette  into  a  test  tube,  having  a  capacity  of 


WATER  AND  PUMPS. 


7 


200  c.c.,  and  provided  with  a  ground  glass  stopper.  Water 
containing  much  lime  is  previously  diluted  with  distilled  water, 
so  that  to  a  determined  number  of  cubic  centimeters  (10,  20, 
or  30)  of  the  water  to  be  tested,  90,  80,  or  70  c.c.  of  distilled 
water  are  added.  A  mark  on  the  tube  indicates  the  point  to 
which  it  is  filled  by  100  c.c.  of  the  fluid. 

Before  adding  the  soap  solution,  the  free  carbonic  acid  is 
partly  removed  by  shaking  the  water. 

As  most  well  waters  have  more  than  120  of  hardness,  only 
10  c.c.  of  the  water  to  be  tested  are  measured  off,  and  diluted 
to  the  mark  with  distilled  water.  Titrated  soap  solution  is 
then  slowly  added  from  a  burette  until,  after  vigorous  shaking, 
a  dense  delicate  lather  is  formed  which  will  hold  for  about  five 
minutes.  The  soap  solution  is  first  added  in  half  cubic  centi- 
meters and  later  on  in  drops.  The  shaking  must  always  be 
done  in  the  same  manner,  and  the  volume  of  the  fluid  amount 
to  100  c.c.  before  the  soap  solution  is  added.  Should  a  second 
experiment  be  necessary,  the  same  quantity  of  water  is  used, 
or,  in  case  but  little  soap  solution  has  been  consumed  for  the 
diluted  water  ( 10:  100),  correspondingly  more  (25  to  50  c.c), 
so  that  the  quantity  of  soap  solution,  which  should  previously  be 
approximately  calculated,  does  not  exceed  45  c.c.  With  the 
assistance  of  the  following  table,  the  respective  degree  of  hard- 
ness which,  in  case  the  water  has  been  diluted,  must  be  multi- 
plied with  the  corresponding  figure,  is  found  from  the  cubic 
centimeters  of  soap  solution  consumed.  (The  corresponding 
figure  is  found  by  dividing  100  by  the  cubic  centimeters  used 
for  the  experiment.) 

3.4  c.c.  soap  solution  consumed 
54 

7.4  « 


The  difference  of  1  c.c.  of  soap  solution  =  0.25  degree  of 
hardness. 


0.5  degree  of  hardness. 
1.0       "  " 
1.5       "  " 
2.0       "  " 


8 


THE  MANUEACTURE  OF  LEATHER. 


1 1.3  c.c.  soap  solu 
13.2  " 
15.1 

17.0  " 
18.9 

20.8  " 


ion  consumed   2.5  degree  of  hardness. 

•    "    3-0 

  3-5 

  4-0 

  4-5 

  5° 


The  difference  of  1  c.c.  of  soap  solution  =  0.26  degree  of 
hardness. 


22.6  c.c.  soap  solu 
24.4 

26.2  " 
28.0  " 
29.8 

31.6  - 


ion  consumed   5.5  degree  of  hardness. 

  6.0 

  6.5 

  7-o 

  7-5 

  8.0 


The  difference  of  1  c.c.  of  soap  solution  =  0.277  degree  of 
hardness. 

33.3  c.c.  soap  solution  consumed   8.5  degree  of  hardness. 


35 -° 
36.7 
384 
40.1 
41.8 


9.0 

9-5 
1 0.0 
10.5 
11.0 


The  difference  of  1  c.c.  of  soap  solution  =  0.294  degree  of 
hardness. 

43.4  c.c.  soap  solution  consumed   1 1.5  degree  of  hardness. 

45.0       "  "  "    12.0       "  " 

The  difference  of  1  c.c.  of  soap  solution  =  0.31  degree  of 
hardness. 

Suppose  50  c.c.  of  the  water  to  be  tested  had  been  placed  in 
the  test  tube  and  diluted  with  50  c.c.  of  distilled  water,  and  had 
consumed  22.6  c.c.  of  soap  solution  for  the  formation  of  lather. 
According  to  the  table  these  22.6  c.c.  of  soap  solution  corre- 
spond to  5.5  degrees  of  hardness.  This  figure  5.5  is  multiplied 
by  2,  which  gives  1 1  as  the  actual  degree  of  hardness  of  the 
water.  (The  figure  2  is  obtained  by  dividing  100  c.c.  by  50 
c.c.) 


WATER  AND  PUMPS. 


9 


2.  Determination  of  Permanent  Hardness. — For  the  determi- 
nation of  the  permanent  hardness  500  c.c.  of  water  are  boiled 
in  a  sufficiently  large  matrass  for  at  least  one  and  a  half  hours, 
a  part  of  the  evaporated  water  being  replaced  by  distilled  water. 
The  boiled  water,  when  cold,  is  poured  into  a  flask  having  a 
capacity  of  500  c.c,  and  the  matrass  rinsed  out  with  distilled 
water,  the  rinsings  being  added  to  the  water  in  the  flask.  The 
latter  is  then  filled  with  distilled  water  up  to  the  mark,  and  the 
entire  contents  filtered  through  a  dry  filter  into  a  dry  test  tube. 
The  degree  of  hardness  of  a  definite  number  of  cubic  centime- 
ters is  then  determined  in  the  above  manner. 

Clark  was  the  first  to  introduce  the  term  "  degrees  of  hard- 
ness," I  degree  corresponding,  according  to  him,  to  1  part 
(grain)  of  calcium  carbonate  or  its  equivalent  of  another  cal- 
cium salt,  or  equivalent  quantities  of  magnesia  or  magnesium 
salts  in  70,000  parts  (=  I  gallon)  of  water,  At  the  present 
time  1  degree  of  hardness  is  suitably  estimated  as  equal  to  1 
part  of  calcium  oxide  in  ioo.OOO  parts  of  water.  The  German 
degrees  of  hardness  are  reduced  to  English  by  multiplying  the 
degrees  found  by  5  and  dividing  by  4,  the  reduction  of  English 
to  German  degrees  being  vice  versa  accomplished  by  multiply- 
ing by  4  and  dividing  by  5.  In  France  1  degree  of  hardness  is 
calculated  as  equal  to  I  part  of  calcium  carbonate  in  100,000 
parts  of  water,  1  degree  of  hardness  being  therefore: 
In  Germany  =  1  o  milligrams  of  calcium  oxide  in  1  litre  of  water. 
In  France  =  5.6  milligrams  of  calcium  oxide  in  I  litre  of  water, 
or  an  equivalent  quantity  of  magnesia  or  magnesium 
salts. 

SOFTENING  WATER. 

There  have  been  proposed  numerous  methods  for  softening 
and  purifying  water.  Some  effect  a  chemical  reaction,  others 
act  by  a  mechanical  process,  while  others,  such  as  oak  sawdust, 
act  both  chemically  and  mechanically ;  the  tannic  acid  which  it 
contains  forming  tannates  of  lime  and  magnesia  by  the  decompo- 
sition of  the  carbonates,  and  these  tannates,  on  account  of  their 
low  specific  gravity,  float  about  the  water.    The  sulphates  and 


IO 


THE  MANUFACTURE  OF  LEATHER. 


chlorides  are  prevented  from  agglutinating  into  a  crust  by  the 
mechanical  action  of  the  sawdust.  Such  anti-incrustation 
remedies  as  oil-cake,  potatoes  and  other  starchy  matter,  glue, 
ofifal  of  hoofs  and  horns,  tobacco  juice,  Irish  moss,  peat,  tow, 
hemp,  etc.,  envelop  the  particles  of  lime  and  deposit  them  in 
the  form  of  sludge. 

Clay  also  precipitates  the  lime  salts  in  the  above  manner. 
Tannic  acid  does  not  act  upon  sulphates  and  chlorides,  neither 
is  sulphate  of  lime  altered  by  acetic  acid,  the  action  of  both 
these  acids  being  to  convert  the  carbonates  into  soluble  ace- 
tates, and  of  course  in  this  action  both  tannic  acid  and  acetic 
acid  are  absorbed  and  the  work  which  they  might  do  in  the  tan 
pit  is  lessened.  Both  tannic  and  acetic  acids  are  employed  to 
purify  water,  but  the  employment  of  these  acids  is  expensive, 
and  their  place  can  be  taken  by  cheaper  acids  and  alkalies. 

Borax  is  the  best  agent  that  can  be  used  for  purifying  water 
for  the  use  of  tanners  and  curriers.  Its  price  is  now  about  5^ 
cents  a  pound,  and  5  or  more  pounds  of  borax  will  soften  one 
thousand  gallons  of  water,  such  as  is  used  by  the  average  tan- 
ner. Some  harder  waters  will  require  a  little  more  borax,  and  at 
the  present  price  of  hemlock  and  oak  bark,  will  save  him  on  an 
average  about  $1.50,  that  is,  the  tanner  by  buying  about 
twenty-five  cents  worth  of  borax  will  be  $1.50  in  pocket. 

To  soften  one  thousand  gallons  of  water  5  pounds  of  borax 
are  used.  It  is  dissolved  in  boiling  water  and  poured  into  the 
vat  or  tank  under  vigorous  stirring. 

The  laundry  men  have  tried  all  sorts  of  chemicals  for  soften- 
ing the  water  which  they  use  for  washing  clothes,  and  they 
have  found  none  so  harmless,  cheap  and  effective  as  borax. 
The  large  packers  of  this  country  have  tried  all  sorts  of  chem- 
icals for  preserving  their  meats,  but  are  now  using  borax  be- 
cause of  its  cheapness  and  preserving  qualities. 

The  foregoing  are  two  reasons  why  the  tanners  of  all  kinds  of 
hides  and  skins  should  use  borax  in  their  soaks,  as  the  soaks  are 
thus  kept  fresh  and  prevented  from  becoming  putrid  or  foul,  with 
the  consequent  withdrawing  of  valuable  gelatine  from  the  hide  or 


WATER  AND  PUMPS. 


I  I 


skin  under  treatment.  By  the  use  of  borax  in  the  soaks  a  firmer, 
heavier  and  more  solid  leather  can  be  produced  by  this  saving  of 
gelatine.  In  the  leaches  borax  is  equally  invaluable  for  soften- 
ing the  water  before  it  goes  on  the  tan  bark,  because  of  the 
large  saving  of  money  which  it  effects.  Of  course  the  tannic 
acid  will  soften  the  water,  but  the  hardness  of  the  water  has  to 
be  overcome  by  the  tannin  before  the  water  itself  can  become 
effective. 

Borax  is  one  of  the  gentlest  of  the  alkalies  and  is  one  of  the 
most  perfect  of  the  cleansers.  It  will  clean  a  hide  or  skin  thor- 
oughly, which  is  a  most  desirable  point  in  tanning,  and  by  ren- 
dering the  water  soft  it  will  act  upon  the  tan  bark  quickly  under 
any  system  of  leaching. 

Borax  is  largely  used  by  dyers  and  colorers  of  leather  for 
rendering  the  water  soft  and  also  as  a  mordant,  and  thus  pre- 
venting the  absorption  of  too  much  coloring  matter  or  dry  stuffs, 
and  giving  a  more  uniform  color  and  lustre. 

Borax  is  very  largely  used  by  the  manufacturer  of  glazed  kid, 
not  only  in  soaking  and  cleansing  the  skin,  but  it  is  a  fine  mor- 
dant and  gives  a  uniform  color  to  the  skins.  It  is  well  known 
that  in  the  treatment  of  colored  goods  in  the  laundry,  borax 
is  used  in  the  water  to  prevent  the  colors  from  running  ;  it  fixing 
them.  Borax  has  heretofore  been  a  little  too  high  in  price  to 
be  generally  used  by  the  tanner  or  currier,  but  now  the  price 
has  fallen  so  low  as  to  bring  it  within  his  reach,  and  he  should 
improve  his  opportunity. 

It  was  formerly  imported  from  abroad,  but  since  the  discov- 
eries of  this  substance  on  the  Pacific  Coast  nearly  all  the  borax 
used  in  this  country  comes  from  there,  and  as  a  consequence 
the  price  has  fallen  to  its  present  low  point. 

A  clean  hide  or  skin  will  tan  more  quickly  than  a  dirty  one, 
hence  borax  will  hasten  the  tanning  process  and  thus  save  time 
and  money. 

It  is  to  be  observed  that  water  evaporates  at  all  temperatures, 
and  its  solvent  properties  far  exceed  those  of  any  other  known 
liquid.    The  softer  the  water  the  greater  its  solvent  properties. 


I  2 


THE  MANUFACTURE  OF  LEATHER. 


A  very  large  proportion  of  all  the  different  salts  are  more  or 
less  soluble  in  it,  the  solubility  increasing  generally  as  the  tem- 
perature rises,  so  that  a  hot,  saturated  solution  deposits  crystals 
on  cooling.  There  are  a  few  exceptions  to  this  rule,  one  of  the 
most  remarkable  of  which  is  common  salt,  the  solubility  of 
which  is  nearly  the  same  at  all  temperatures,  the  hydrate  of 
lime  (slaked  lime)  being  more  soluble  in  cold  than  in  hot  water, 
sulphate  of  lime  being  also  less  soluble  in  hot  than  in  cold  water, 
and  insoluble  at  3020  F.,  or  between  2840  and  3020  F. 

Water  is  one  of  the  most  potent  agencies  with  which  the 
tanner  has  to  deal,  and  the  harder  the  water  the  less  profit 
there  will  be  in  the  tanning  and  currying  industries. 

PUMPS. 

The  methods  of  obtaining  water  in  tanneries  vary  greatly, 
and  we  will  here  enter  briefly  into  the  subject  of  pumps. 

There  is  no  mention  made  in  history  of  pumps  prior  to  the 
year  200  B.  C.  The  Chinese  cannot  claim  any  priority  in  this 
special  branch,  which  is  peculiar,  when  we  consider  their 
manner  of  irrigation.    A  pump  is  a  rarity  with  them. 

A  tanner's  pump  is  not  a  very  intricate  machine,  and  its  parts 
are  comparatively  few.  But  its  action,  or  want  of  it,  sometimes 
makes  it  seem  most  mysterious.  To  those  readers  who  have 
not  considered  the  question  of  water  dispensation,  the  remark 
that  pumping  machinery  stands  prominent  among  the  various 
branches  of  engineering  may  seem  to  allow  of  discussion.  A 
few  instances  will  very  soon  give  ample  proof.  How  could  our 
coal  be  obtained  and  our  mines  worked,  if  not  for  the  pumping 
plant? — our  water  supply  obtained,  or  our  sewage  and  chem- 
ical works  carried  on?  When  man  enters  Nature's  store-house 
in  search  of  wealth,  he  finds  water  ever  ready  to  dispute  his 
supremacy;  it  may  be  in  a  constant  stream,  varying  only  with 
the  season ;  oftentimes  vast  quantities  are  stored  in  crevices  of 
the  rocks.  Some  idea  of  the  quantity  of  water  raised  will  be 
given  when  it  is  known  that  often  its  weight  is  double  and 
treble  that  of  other  material  raised,  and  is  frequently  30  per 
cent,  in  coal  mines. 


WATER  AND  PUMPS. 


13 


Rude  nations  have  not  possessed  the  machine,  simple  as  it 
is,  but  have  always  resorted  to  a  more  laborious  method  to  ob- 
tain water.  In  the  early  ages  it  does  not  appear  to  have  been 
known  to  the  Greeks  or  Romans.  Although  the  pump  was 
invented  200  B.  C,  it  was  not  until  the  beginning  of  the  seven- 
teenth century  that  its  true  principles  were  understood ;  al- 
though in  1636  fire  engines  were  built  in  Holland,  and  from 
which,  as  far  as  general  principles  are  concerned,  no  improve- 
ments have  been  made. 

The  pumps  commonly  used  for  raising  water  from  wells  may 
be  divided  into  two  classes — lifting  pumps  and  forcing  pumps. 
The  lifting  pumps  may  be  again  subdivided  into  two  varieties, 
namely,  those  with  a  hollow  piston  and  those  with  a  solid  or 
plunger  piston. 

Lifting  pumps  with  a  hollow  piston,  called  also  atmospheric 
pumps.  This  variety,  in  its  simplest  form,  consists  of  the  fol- 
lowing parts : 

A  cylinder  or  tube,  in  which  is  fixed  a  valve  opening  upward, 
and  above  which  works  a  piston  provided  with  a  valve  also 
opening  upward.  The  part  of  the  cylinder  in  which  the  piston 
works  is  called  the  body  of  the  pump,  and  is  the  only  part 
which  need  be  bored  with  any  great  accuracy.  The  top  of  the 
cylinder  may  be  opened  or  closed,  it  matters  not  which,  but 
somewhere  above  the  level  to  which  the  piston  ascends  there 
must  be  an  orifice  for  discharging  the  water. 

The  action  of  the  common  atmospheric  pump  is  so  simple, 
and  is  so  well  known  to  every  school  boy,  that  it  will  be  un- 
necessary here  to  dwell  upon  it.  The  cylinder  is  made  of  vari- 
ous materials,  as  wood,  iron,  or  copper,  and  frequently  the 
lower  part  below  the  fixed  valve  is  a  mere  iron  pipe  furnished 
with  a  strainer  at  its  lower  extremity.  The  fixed  valve  in  this 
kind  of  pump  must  be  placed  at  such  a  level  that  the  depth 
from  it  to  the  surface  of  the  water  in  the  well  must  never  ex- 
ceed the  height  of  a  column  of  water  which  will  balance  the 
atmospheric  pressure  or  weight  of  the  atmosphere.  This 
weight  is  measured  in  the  barometer  by  a  column  of  mercury, 


THE  MANUFACTURE  OF  LEATHER. 


which  varies  in  different  parts  of  the  world,  and  at  different 
altitudes,  from  28  to  31  inches.  Thus,  an  atmospheric  pump 
at  the  level  of  the  sea  may  have  its  fixed  valve  several  feet 
higher  than  a  similar  pump  working  on  the  top  of  a  high 
mountain.  The  height  at  which  the  mercury  stands  in  a 
barometer  at  any  given  place  affords,  in  fact,  a  tolerably  prac- 
tical measure  of  the  height  to  which  water  will  rise  in  a  vacuum 
when  pressed  by  the  external  atmosphere.  Thus,  in  theory, 
where  the  mercury  stands  in  the  tube  of  a  barometer  at  a 
height  of  30  inches,  the  sucker  or  fixed  valve  of  an  atmospheric 
pump  may  be  placed  30  feet  above  the  surface  of  water  in  a 
well.  In  practice,  however,  owing  to  imperfection  of  materials, 
fluctuations  of  level  in  the  water,  and  other  causes,  this  differ- 
ence of  level  is  too  great,  and  should  not  really  exceed  25  feet. 
In  shallow  wells,  therefore,  which  are  not  more  than  about  27 
feet  in  depth,  the  part  of  the  cylinder  or  pump  above  the  fixed 
valve  need  never  exceed  the  length  of  the  slope  or  space 
through  which  the  piston  works.  In  deep  wells  the  ascending 
part  of  the  cylinder  above  the  body  of  the  pump  in  which  the 
piston  works  may  be,  theoretically,  of  any  height.  There  are 
difficulties,  however,  connected  with  the  valves  in  the  movable 
piston  which  render  it  inconvenient  to  have  the  lift  in  this  kind 
of  pump  much  more  than  100  feet.  Whatever  may  be  the 
height  of  the  column  of  water  above  the  movable  piston,  it  is 
evident  that  the  absolute  weight  of  this  whole  column  has  to  be 
lifted  at  each  stroke  of  the  piston,  and  for  this  reason  atmo- 
spheric pumps,  which  are  worked  by  hand,  have  scarcely  any 
of  the  pump  above  the  piston,  as  otherwise  the  weight  of  water 
to  be  lifted  at  each  stroke  would  be  too  great  for  the  power  to 
be  applied.  This  practically  limits  the  height  to  which  water 
can  be  raised  from  wells  by  common  atmospheric  pumps 
worked  by  hand  to  about  25  feet. 

In  deep  wells,  however,  when  pumps  are  worked  by  horse  or 
steam  power  this  objection  does  not  apply,  and  if  the  power  be 
sufficient  to  raise  at  each  stroke  the  whole  column  of  water 
above  the  piston,  the  length  of  the  cylinder  above  this  piston 


WATER  AND  PUMPS. 


15 


is  only  limited  by  the  practical  considerations  before  alluded  to 
in  connection  with  the  valves.  It  should  be  observed  that  the 
common  atmospheric  pump  is  seldom  or  never  used  in  water- 
works for  the  purpose  of  raising  water. 

In  the  manufacture  of  waxed-calf,  it  is  important  that  there 
should  be  a  uniform  temperature  of  the  water  in  which  the 
skins  are  soaked,  and  but  few  of  the  best  manufacturers  of  this 
class  of  leather  in  France  or  Germany  soak  the  skins  in  run- 
ning water,  because  it  is  extremely  cold  in  winter  and  warm 
in  summer.  In  default  of  water  from  a  live  source,  it  may 
be  drawn  from  a  cistern ;  but,  it  may  be  said,  it  requires  a 
large  quantity  of  water,  and  that  it  will  be  costly  to  draw  it 
to  the  surface.  But  it  is  very  seldom  that  a  tannery  does  not 
possess  a  horse  or  a  steam  engine ;  the  horse  is  often  idle  in 
the  stable  ;  the  engine  has  always  a  little  power  to  spare  above 
its  requirements ;  or  by  means  of  the  simplest  machinery  a 
double-action  pump  may  be  constructed  and  made  to  work  by 
horse  or  steam  power,  and  in  this  way  there  can  be  obtained 
from  2,000  to  2,500  gallons  per  hour  or  more  if  desired.  There 
should  be  in  the  centre  of  the  tannery  or  in  one  of  the  corners, 
a  large  tank  raised  at  least  six  feet  above  the  ground  ;  the 
water,  pumped  into  the  tank,  can  be  distributed  at  will  over  the 
whole  establishment.  The  total  expense  may  amount  to  $500 
or  $600;  and  such  a  figure  is  not  large  in  consideration  of  the 
importance  of  the  result :  to  have  always  at  disposal  a  quantity 
of  pure  water  and  of  an  equal  temperature. 

If  the  tannery  is  a  large  one,  and  requires  more  water  than 
can  be  furnished  by  this  simple  outfit,  then,  in  our  opinion,  the 
tanner  can  not  do  better  than  to  follow  the  example  of  the 
American  Oak  Leather  Company,  of  Cincinnati,  Ohio,  and  the 
Henry  Lang  Co.,  patent  leather  manufacturers  of  Newark, 
N.  J.,  who  have  recently  put  in  a  pump  with  a  pipe  about  200 
feet  deep,  for  pumping  water  by  compressed  air  by  the  Pohle 
system. 

Tanners  and  those  interested  in  mining  and  hydraulics  will 
be  glad  to  have  some  account  of  the  Pohle  system  of  raising 


i6 


THE  MANUFACTURE  OF  LEATHER. 


water  from  non-flowing  wells,  mines,  etc.,  which  has  been  intro- 
duced by  the  Ingersoll-Sergeant  Drill  Company,  of  No.  26 
Cortlandt  street,  New  York,  N.  Y. 


Fig.  1. 


! 

la 


The  following  description  is  given  by  the  makers : 
The  pump  proper,  shown  in  Fig.  1,  consists  of  only 
two  plain  open-ended  pipes,  the  larger  one  with  an 
enlarged  end  piece  constituting  the  discharge  pipe, 
and  the  smaller  one  let  into  the  enlarged  end  piece 
of  the  discharge  pipe  constitutes  the  air  inlet  pipe, 
through  which  the  compressed  air  is  conveyed  to 
the  enlarged  end  piece  to  the  under  side  of  the 
water  to  be  raised.  No  valves,  buckets,  plungers, 
rods  or  other  moving  parts  are  used  within  the  pipes 
or  well. 

In  pumping,  compressed  air  is  forced  through  the 
air  pipe  into  the  enlarged  end  at  the  bottom  of  the 
water  pipe,  thence  by  the  inherent  expansive  force 
of  the  compressed  air,  layers  or  pistons  of  air  are 
formed  in  the  water  pipe,  which  lift  and  discharge 
the  water  layers  through  the  upper  end  of  the  water 
discharge  pipe.  At  the  beginning  of  the  operation 
the  water  surface  outside  of  the  pipe  and  the  water 
surface  inside  of  the  pipe  are  at  the  same  level ;  hence  the  ver- 
tical pressures  per  square  inch  are  equal  at  the  submerged  end 
of  the  pipe,  outside  and  inside.  As  air  is  forced  into  the  lower 
end  of  the  water  pipe,  it  forms  alternate  layers  with  the  water, 


WATER  AND  PUMPS. 


■7 


so  that  the  pressure  per  square  inch  of  the  column  thus  made 
up  of  air  and  water,  as  it  rises  inside  of  the  water  pipe,  is  less 
than  the  pressure  of  water  per  square  inch  outside  of  the  pipe 
Owing  to  this  difference  of  pressure,  the  water  flows  contin- 
ually from  the  outside  to  within  the  water  pipe  by  gravity  force, 
and  its  ascent  through  the  pipe  is  free  from  shock,  jar  or  noise 
of  any  kind. 

These  air  sections  or  strata  of  compressed  air  form  water- 
tight bodies,  which,  in  their  ascent  in  the  act  of  pumping,  per- 
mit no  "slipping"  or  back  flow  of  water.  As  each  air  stratum 
progresses  upward  to  the  spout,  it  expands  on  its  way  in  pro- 
portion as  the  overlying  weight  of  water  is  diminished  by  its 
discharge,  so  that  the  air  section,  which  may  have  been  say  50 
pounds  per  square  inch  at  first,  will  be  only  1.74  pounds  when 
it  underlies  a  water  layer  of  four  feet  in  length  at  the  spout, 
until  finally  this  air  section,  when  it  lifts  up  and  throws  out  this 
four  feet  of  water,  is  of  the  same  tension  as  the  normal  atmo- 
sphere ;  thus  proving  that  the  whole  of  its  energy  was  used  in 
work,  and  that  this  pump  is  a  perfect  expansion  engine. 

As  the  weight  of  the  water  outside  of  the  discharge  pipe  (the 
head)  is  one  third  greater  per  square  inch  than  the  aggregate 
water  sections  within  the  pipe  when  in  operation,  it  follows  that 
the  energy  due  to  this  one-third  greater  weight  is  utilized  in 
overcoming  the  resistance  of  entry  into  the  pipe,  and  all  the 
friction  within  it. 

The  Pohle  "air  lift"  pump  gives  ninety  per  cent,  of  efficiency 
from  the  air  receiver  in  water  pipes  of  large  diameter,  and  as 
a  rule,  above  eighty  per  cent.  It  retains  this  efficiency  with- 
out repairs,  or  until  the  pipes  rust  through,  whereas  ordinary 
bucket  and  plunger  pumps  gradually  lose  efficiency  from  the 
first  stroke  they  make,  and  lose  it  rapidly  if  the  water  contains 
sand  or  is  acid  in  character.  It  has  been  estimated  by  compe- 
tent experts,  that  under  favorable  conditions  and  large  diame- 
ters of  water  and  air  pipes,  1,000,000  gallons  of  water  can  be 
raised  1 00  feet  high  with  one  and  a  half  tons  of  good  coal. 

The  air  reservoirs  are  all  strongly  made  of  homogeneous 


iS 


THE  MANUFACTURE  OF  LEATHER. 


steel,  tested  and  guaranteed  at  working  pressures  of  110 
pounds ;  they  are  provided  with  the  proper  openings  for  inlet 
and  outlet  pipes,  manhole  and  head,  drain  cocks,  pressure  gage 
and  safety  valve. 

As  the  pump  has  no  valves,  no  standing  water  remains  in  the 
pump  column  after  the  operation  of  pumping;  it  recedes  into 
the  well,  and  there  is  none  left  to  freeze  in  cold  weather.  The 
capacity  of  the  pump  is  unlimited,  and  with  the  proper  propor- 
tions of  air  to  the  water,  will  work  efficiently  in  pipes  several 
feet  in  diameter.  Estimates  have  been  made  which  indicate 
that  a  thirty-inch  pipe  will  deliver  16,660  gallons  per  minute, 
equal  to  1,000,000  gallons  per  hour. 

Experience  has  proved  that  by  the  use  of  this  constant  upward 
flow  of  water,  artesian  wells  have  been  freed  from  their  accumu- 
lated sedimentary  deposits,  as  well  as  that  lodged  in  the  fissures 
and  crevices  of  their  wall  rock,  and  have  been  thus  made  to 
yield  greater  quantities  of  water  than  they  ever  did  before.  For 
chemical  uses,  and  for  the  liquids  of  the  arts,  there  is  no  super- 
ior method  to  the  "Air  Lift."  It  is  used  successfully  for  rais- 
ing sulphuric  acid  of  high  specific  gravities,  and  is  well  adapted 
for  ore  leaching  works,  vinegar  works,  sugar  refineries,  dye 
works,  tanneries,  paper  pulp  works,  etc. 

This  pump  can  be  run  with  motor,  water  wheel,  steam,  oil  or 
gas  engine,  or  any  other  source  of  power. 

It  makes  a  much  greater  difference  in  the  manufacture  of 
waxed-calf  than  with  any  other  class  of  leather,  whether  the 
water  is  hard  or  soft ;  still  some  prefer  it  soft,  as  it  contains  less 
calcareous  substances  than  hard  water,  which  is,  as  we  have 
explained,  often  saturated  with  earthy  salts.  We  have  not  at- 
tempted to  give  in  this  work  the  analyses  of  all  the  waters  that 
trickle  through  our  soil ;  it  is  the  tanner's  business  to  become 
acquainted  with  the  quality  of  the  water  he  has  at  his  disposal, 
and  to  utilize  it  according  to  the  elements  it  contains.  Study 
the  water ;  if  it  is  soft  the  soaking  will  be  done  promptly,  if  it 
is  hard  it  will  take  longer ;  but,  any  way,  there  is  a  certainty  of 
arrriving  at  the  same  result;  that  is  the  aim. 


* 


WATER  AND  PUMPS. 


19 


Fig.  2  illustrates  a  Pohle  Air  Lift  Plant  at  the  works  of  the 
Henry  Lang  Co.,  Patent  Leather  Manufacturers  of  Newark, 
N.  J.  It  has  recently  been  installed,  and  is  giving  entire  satis- 
faction. The  owners  of  the  plant  are  enthusiastic  over  the  work 
it  is  accomplishing.   Its  normal  work  is  10,000  gallons  of  water 

Fig.  2. 


DISCHARGE  PIPE  AND  WATER  TANK  OITSIDE  OF  HENRY  LANG  CO.'S  FACTORY.  RAISING 
WATER  BY  THE  POHLE  AIR  LIFT. 

every  hour.  The  outfit  comprises  an  Ingersoll-Sergeant  Class 
"F"  Air  Compressor,  an  Air  Receiver,  and  the  Pohle  device  in 
the  well.  The  total  depth  of  the  well  is  204  feet;  diameter,  six 
inches.  The  water  level  is  twenty-five  feet  beneath  the  surface. 
The  total  lift  from  the  level  in  the  well  to  the  tank  is  eighty-five 
feet.    There  is  a  steady  supply  of  water. 


20 


THE  MANUFACTURE  OF  LEATHER. 


When  the  conditions  that  surround  other  pumping  outfits  are 
compared  with  the  simplicity  of  the  Pohle  Air  Lift  method,  the 
differences  are  vast  in  favor  of  the  latter.  This  plant  replaced 
a  deep  well  pump  which  failed  to  give  the  necessary  supply  of 
water.  In  the  illustration,  Fig.  2,  the  view  shows  that  the  dis- 
charge pipe  is  exposed  to  all  sorts  of  weather.  That,  however, 
is  no  disadvantage  to  the  Pohle  Air  Lift  Pump,  because  when 
the  pump  is  not  in  operation  the  water  does  not  stand  in  the 
pipe,  but  falls  back  into  the  well,  thus  obviating  the  danger  of 
freezing,  rust,  or  other  detrimental  effects. 

For  a  factory,  tannery,  brewery,  paper-mill,  or  other  estab- 
lishments, the  plant  described  can  be  installed  at  a  reasonable 
outlay.  The  owners  of  this  plant  say  in  a  letter  that  it  is  the 
best  pump  ever  brought  to  their  notice,  and  that  it  far  exceeds 
their  expectations. 


CHAPTER  II. 


ANIMAL  SKIN. 

In  the  production  of  leather  there  are  two  classes  of  raw  pro- 
ducts with  which  the  tanner  has  to  deal ;  they  are — 

1.  Hides  and  skins  to  be  converted  into  leather,  and 

2.  Materials  by  the  aid  of  which  the  conversion  or  tan- 

ning is  effected. 

The  object  of  the  present  chapter  is  to  explain  the  structure 
of  the  skin  and  its  behavior  with  reagents,  without  which 
knowledge  an  intelligent  prosecution  of  the  art  of  tanning  is 
rendered  difficult  and  at  times  hazardous. 

The  structure  of  animal  skin  consists  of  several  readily  dis- 
tinguishable layers,  which  behave  differently  in  a  chemical  as 
well  as  in  a  physical  respect. 

The  upper  part  of  the  skin  in  which  the  coat  of  hair,  wool,  or 
fur  is  rooted,  is  termed  the  epidermis  or  cuticle,  next  beneath 
this  is  the  corium  or  true-skin,  and  placed  next  to  this  is  the 
under-skin. 

The  epidermis  is  composed  of  two  layers  :  — 

1.  A  tissue  analogous  to  the  corneous  matter  of  the  hoofs, 
horns,  nails,  and  hair,  and  is  composed  of  layers  of  nucleated 
epithelium  cells,  which  when  first  formed  are  spherical,  gradu- 
ally becoming  dry  and  flattened  ;  the  deeper  layers  being  more 
distinctly  cellular,  while  the  outer  layer  is  scale-like,  and, 

2.  An  inferior  or  basis-layer,  Malpighi's  net  {rete  Malpi- 
ghianum),  which  consists  of  a  layer  of  cells  charged  with  fluid, 
and  serves  to  feed  or  renew  the  horny  tissue,  being  in  its  turn 
supplemented  by  vessels  situated  in  the  corium. 

The  epidermis  does  not  combine  with  tannin  or  other  sub- 
stances by  the  agency  of  which  leather  is  produced.    Hence  it 

(21  ) 


22 


THE  MANUFACTURE  OF  LEATHER. 


becomes  useless  to  the  tanner,  and  therefore  the  first  process 
to  which  hides  and  skins  are  subjected  by  him  is  that  for  re- 
moving the  hair  and  epidermis,  and  the  portion  of  the  skin 
thereby  exposed  is  technically  termed  the  "  grain  side." 

The  corium  or  true  skin  is  divided  into  an  intermediate  layer 
next  to  the  epidermis,  and  is  the  actual  leather-skin. 

Both  are  made  up  of  interlaced  bundles  of  connective  tissue 
fibres,  placed  crosswise  above  each  other,  and  running  parallel 
with  the  surface  of  the  skin ;  but  being  more  or  less  filled  with 
fluid  matter  that  serves  to  renew  the  cuticle  and  maintain  the 
skin  in  a  pliant  and  moist  condition.  On  treating  the  skin  with 
water  these  matters  are  removed,  and  ultimately  there  remains 
but  the  fibrous  portion  saturated  with  water.  In  this  state  it 
appears  semi-transparent,  and  if  the  water  be  expelled  by  a 
gentle  heat,  it  assumes  the  physical  appearance  of  horn,  con- 
stituting only  about  32^  to  33  per  cent,  of  the  raw  hide. 

The  quality  of  the  leather  which  can  be  produced  from  a  skin 
depends  upon  the  thickness,  flexibility  and  strength  of  the 
corium,  which  exceeds  the  combined  thickness  of  all  the  other 
layers  forming  the  remainder  of  the  skin. 

A  peculiar  albuminoid  substance  (cori'in)  is  stored  between 
the  separate  fibres  of  the  corium,  which  substance  in  a  dry 
state  connects  and  cements  together  the  raw  skin  fibres. 

The  under-skin  consists  of  a  loose  connective  tissue,  in  which 
the  sweat  and  fat  glands,  the  blood-vessels  and  muscular  fibres 
are  embedded.  It  is  previously  removed  in  the  "  beam  house" 
of  the  tannery,  and  takes  no  part  in  the  tanning  process. 

The  side  upon  which  the  connective  tissue  of  the  under  skin 
is  located  is  technically  designated  as  the  "  flesh  side." 

Fig.  3  shows  an  enlarged  transverse  section  of  the  skin. 

D  is  the  connective  tissue  of  the  under-skin  showing  the 
sweat  glands  g,  with  the  ducts  h,  through  which  this  secretion 
passes  out  to  the  surface  of  the  skin  ;  b  is  the  Malpighi  net,  and 
d  the  corium;  c,  papillas  of  the  skin;  e,  f,  lobules  of  adipose 
tissue ;  i,  the  external  orifices  of  the  sweat  or  perspiratory 
glands;  k,  hair  follicle;  hair  papilla;  n,  hair  bulb;  0,  shaft 
of  hair  in  hair  follicle;  p,  openings  of  the  sebaceous  glands. 


ANIMAL  SKIN. 


23 


The  horny  layer  of  the  epidermis,  a,  shows  on  different 
places,  as  at  /,  such  structures  as  hair,  wool,  bristles,  etc., 
which,  as  seen  in  the  illustration,  are  not  embedded  immediately 
in  the  surface,  but  in  capsules  or  shafts,  called  ''hair  sacs"  or 
"hair  roots,"  reaching  from  the  epidermis  to  the  actual  corium. 
In  these  sac-like  depressions  the  hair  is  fastened  by  means  of 
"hair  bulbs."  The  hair  is  coated  with  a  protective  layer  of  fat 
by  small  fat  glands,  the  follicles  of  which  enter  the  upper  part 
of  the  hair-sac. 


Fig.  3. 


D 


Malpighi's  rete  mucosum  accompanies  the  bottom  of  the 
hair  sac,  the  walls  of  the  latter  consisting  of  flat  epithelial  cells, 
which  develop,  only  in  another  form,  the  hair  itself. 

The  horny  shaft  of  the  hair  is  a  section  projecting  above  the 
skin,  and  when  completely  developed  is  provided  with  a  minute 
epithelium,  forming  the  upper  skin  of  the  hair. 

In  boiling  with  water  the  connective  tissue  fibres  are  con- 
verted into  glue,  the  other  constituents  taking  no  part  in  the 


24 


THE  MANUFACTURE  OF  LEATHER. 


glue  formation.  The  chemical  process  taking  place  during  the 
latter  operation  is  not  yet  thoroughly  understood.  The  rela- 
tions of  the  glue-yielding  tissues  to  the  glue,  seem  to  be  similar 
to  those  existing  between  starch  and  paste.  Starch,  as  well  as 
the  glue-yielding  tissues,  is  a  body  of  an  equally  pronounced 
nature,  both  being  insoluble  in  cold  water  and  remaining  unal- 
tered within  certain  limits.  By  boiling  with  water,  they  en- 
tirely lose  their  organized  structure  and  form  a  solution,  which 
on  cooling  separates,  in  glue,  a  colorless  jelly,  and  in  starch  a 
body  very  similar  to  glue. 

The  skin,  when  slowly  and  completely  dried  in  the  air  and 
stored  in  a  dry  place,  can  be  kept  for  a  long  time.  When  dried 
by  exposure  to  strong  .sun  heat,  it  undergoes  an  alteration 
having  an  injurious  effect.  The  fibres  of  such  skin,  after  com- 
plete softening  by  soaking,  which  can  only  be  accomplished 
with  great  difficulty,  show  very  little  strength.  This  excessive 
effect  of  heat  may  even  cause  the  skin  fibres  to  dissolve,  in 
soaking,  into  a  glue-like  jelly,  as  has,  for  instance,  been  fre- 
quently observed  in  buffalo  skins  carelessly  dried  by  exposure 
to  strong  sun  heat. 

Moist  skins  left  to  themselves  decompose  in  a  short  time  with 
the  usual  products  of  putrefaction  making  their  appearance. 

Covered  with  salt  or  immersed  in  strong  brine,  skins  can  be 
kept  for  a  long  time.  By  adding  borax  to  the  brine  the  quan- 
tity of  salt  used  can  be  greatly  reduced,  one  pound  of  borax 
doing  the  work  of  five  pounds  of  salt,  and  it  at  the  same  time 
preserves  the  skin  in  much  better  condition  than  when  salt 
alone  is  used. 

The  chemical  and  morphological  constitution,  as  far  as  inter- 
esting to  us,  may  be  briefly  given  as  follows:  — 

"The  connective  tissue  fibres  or  fibrillar  form  the  morpho- 
logical structure  of  the  skin  tissue,  the  intercellular  substance 
or  coriin,  as  has  been  conclusively  shown  by  Rollet,*  and  later 
by  Reimer.t  lying  between  them. 

*  Wiener  Akademieberichte,  30,  37,  39,  308;  and  Dingl.  Polyt.  Journal,  149,  298. 
t  Dingier,  Polyt.  Journal,  143,  205. 


ANIMAL  SKIN. 


2  5 


The  intercellular  substance  is  an  albuminous  body,  according 
to  Roller,  and  Reimer,  soluble  in  lime  and  baryta-water,  and 
also,  according  to  Reimer,  in  a  10  per  cent,  solution  of  common 
salt,  while  in  one  of  greater  or  less  concentration  it  remains  in- 
soluble. This  behavior  towards  solutions  of  common  salt  and 
lime-water  can  therefore  be  used  for  separating  it. 

To  prepare  coriin  the  skin  is  washed  with  water  until  all  the 
soluble  albuminoid  substances  are  extracted.  The  skin  is  then 
placed  in  saturated  lime-water  six  to  eight  days,  which  dissolves 
all  the  coriin.  The  fluid  is  then  filtered,  and  dilute  acetic  or 
hydrochloric  acid  added  until  the  appearance  of  a  slight  acid 
reaction.  The  coriin  is  separated  as  a  flaky  precipitate  which, 
by  standing  quietly,  settles  on  the  bottom. 

To  obtain  the  coriin  perfectly  pure  and  free  from  an  admix- 
ture of  cell  elements,  it  is  redissolved  in  lime-water,  filtered,  and 
again  precipitated  with  acids.  Coriin  precipitated  from  alka- 
line or  common  salt  solution  is  constant  in  all  respects ;  on  de- 
taching it  from  the  filter  gray  or  gray-white  lamina  are  formed, 
which  on  exposure  to  the  air  assume  a  somewhat  darker  color. 
On  shaking  up  with  water,  it  swells  up  without  actually  dis- 
solving, and  is  converted  into  a  paste-like  mass.  By  diluting 
the  latter  with  water  an  opalizing  fluid  is  obtained,  which  by 
standing  forms  a  precipitate,  nothing  whatever  remaining  in 
solution.  The  addition  of  a  small  quantity  of  common  salt  in- 
creases the  swelling  capacity,  while  that  of  a  larger  quantity 
promotes  solution,  and  that  of  a  saturated  solution  of  common 
salt  effects  precipitation.  By  adding  spirit  of  wine  to  the  sub- 
stance dissolved  or  swelled  in  water,  a  flaky  precipitate  is 
separated. 

After  removing  the  spirit  of  wine  the  flakes  act  in  the  same 
manner  as  before.  Precipitation  may  also  be  effected  by  ether, 
but  as  the  precipitate  for  some  time  remains  in  contact  with 
the  ether,  it  can  be  swelled  only  with  difficulty.  Most  of  the 
alkaline  salts  and  alkaline  earths  have,  like  common  salt,  a  dis- 
solving and  swelling  effect  upon  coriin,  small  quantities  of  them 
increasing  its  solubility  in  water,  which  is  a  very  important  fact 
deserving  special  attention  in  tanning. 


26 


THE  MANUFACTURE  OF  LEATHER. 


Most  natural  waters,  as  is  well  known,  contain  small  quanti- 
ties of  alkaline  salts  and  earths.  In  using  such  water  for  swell- 
ing, cleansing  and  washing  the  hides,  the  swelling  influence 
which  these  salts  have  upon  the  coriin  must  be  taken  into 
consideration. 

In  hard  water  containing  much  of  these  salts,  the  skins  must 
remain  for  a  shorter  time  than  in  soft  water,  i.  e.,  such  as  con- 
tains but  a  small  quantity  of  salts,  or  none  whatever. 

In  speaking  of  the  use  of  water  in  the  tannery,  we  have  con- 
sidered this  point  more  closely,  and  the  reader  is  referred  to 
Chapter  I. 

Since  by  repeated  treating  with  lime  or  baryta  water,  fresh 
quantities  of  soluble  substances  can  be  constantly  withdrawn 
from  the  skin,  it  is  not  improbable  that  the  intercellular  sub- 
stance is  a  product  of  decomposition  of  the  connective  tissue 
substance.  This  circumstance  deserves  consideration  in  depil- 
ating the  skins  and  hides  with  lime,  for  if  the  latter  remain  too 
long  in  the  lime,  a  part  of  the  connective  tissue  is  converted  into 
soluble  substance,  which  is  lost  in  the  succeeding  cleansing  of 
the  hides. 

Liming  continued  too  long  gives  poor  weight,  and  besides 
the  strength  of  leather  prepared  from  skins  too  long  limed  is 
impaired. 

Coriin  is  insoluble  in  acetic  acid,  and  only  partly  soluble  in 
dilute  hydrochloric  acid,  the  undissolved  portion  settling  after 
long  standing,  as  a  flaky  precipitate. 

Coriin  is  readily  soluble  in  pure  alkalies  and  solutions  of 
alkaline  earths. 

Potassium  ferrocyanide  and  ferricyanide  produce  no  precipi- 
tation in  acidulated  or  neutral  solution,  but  effect  precipitation 
when  acting  upon  strongly  swelled  coriin. 

Ferric  chloride,  cupric  sulphate,  cupric  chloride,  and  sugar 
of  lead  form  no  precipitate  in  neutral  or  slightly  alkaline  solu- 
tions, while  it  is  produced  by  basic  acetate  of  lead,  excess  of 
tannic  acid  or  basic  acetate  of  iron. 

Coriin  is  free  from  sulphur,  since  on  melting  the  substance 


ANIMAL  SKIN. 


27 


with  potassium  hydrate  no  potassium  sulphide  remains  behind. 

From  the  composition  found  by  the  elementary  analysis, 
Reimer  derives  the  empirical  formula  Ci0HMNI0Oi5. 

The  connective  tissue  substance*  differs  in  many  respects 
from  the  intercellular  substance,  but  principally  by  being  in- 
soluble in  lime-water,  which,  as  we  have  seen,  readily  dissolves 
coriin.  It  is  dissolved  by  acetic,  hydrochloric  and  other  acids, 
but  separates  again  on  neutralization. 

To  prepare  connective-tissue  substance,  place  cleansed  skin 
in  acetic  acid  for  some  time.  The  skin  swells  up  more  and 
more,  while  the  acetic  acid  dissolves  a  portion  of  the  connective- 
tissue  substance.  The  fluid  becomes  of  a  slimy  nature  and 
separates  on  being  diluted  with  water,  filtered  and  neutralized, 
to  a  flaky  precipitate.  To  obtain  the  substance  in  a  pure  state, 
this  precipitate  is  washed  with  lime-water  in  order  to  remove 
coriin  which  may  be  present,  and  is  ayain  dissolved  in  acetic 
acid.  Some  potassium  is  added  to  the  solution  until  only  a 
very  slight  acid  reaction  is  perceptible.  The  fluid  is  then 
saturated  with  common  salt,  the  precipitate,  after  standing 
quietly,  collecting  upon  the  surface.  It  is  filtered,  and  first 
washed  with  slightly  acidulated  water,  and  then  with  pure 
water,  and  finally  dehydrated  with  alcohol. 

Pure  connective-tissue  substance  swells  up  when  placed  in 
water,  and  reassumes  its  original  softness. 

Acetic  acid,  as  previously  mentioned,  dissolves  connective- 
tissue  substance,  the  solution  containing  the  substance  but  it  is 
not  dissolved  as  glue.  Potassium  ferrocyanide  and  ferri- 
cyanide  produce  precipitates  in  the  solution. 

By  boiling  with  water,  the  pure  substance  is  readily  con- 
verted into  glue. 

Pure  lime  water  does  not  dissolve  it;  an  essential  difference 
from  coriin. 

Tannic  acid,  basic  acetate  of  lead,  and  basic  sulphate  of  iron 
produce  precipitates. 

*  Muspratt,  Technische  Chemie,  Bd.  III.  91. 


28 


THE  MANUFACTURE  OF  LEATHER. 


The  empirical  formula  C15H23N506  is  derived  from  the  ele- 
mentary analysis. 

This  being  the  same  composition  as  that  found  by  Cramer 
for  the  fibroin  of  silk,  Reimer  designates  the  matter  extracted 
by  acids  from  the  skin  as  skin  fibroin. 

The  empirical  formulae  calculated  for  coriin  and  skin  fibroin 
give  us  no  information  as  to  the  relation  or  close  analogy  of 
the  two  bodies  to  each  other,  their  chemical  constitution  being 
still  unknown. 

The  most  important  property  of  the  skin  fibre,  which  de- 
serves special  attention  from  a  practical  standpoint,  is  that  it 
swells  up  strongly  in  one-half  per  cent,  solutions  of  inorganic 
acids,  and  is  entirely  dissolved  in  somewhat  concentrated  acids 
if  subjected  sufficiently  long  to  their  action. 

The  swelling  influence  exerted  by  acids  upon  the  skin  fibres 
is,  as  is  well  known,  used  on  the  one  hand  to  make  the  skin 
more  sensitive  for  the  reception  of  the  tanning  material,  and,  on 
the  other,  to  effect  the  isolation  of  the  compound  bundles  of 
connective-tissue  fibres  into  separate  fibres,  increasing  the 
surface  thereby  at  the  same  time.  It  is  self-evident  that  by 
carrying  this  swelling  process  too  far,  the  strength  of  the  fibre 
suffers  injury. 

For  swelling  the  skin  acetic  and  lactic  acids  are  chiefly  used; 
of  these  the  latter  is  more  effective  than  the  former. 


CHAPTER  III. 


VEGETABLE  TANNING  MATERIALS. 

But  few  of  the  large  number  of  vegetables  containing  tannic 
acid  are  used  in  tanning,  though  in  modern  times  the  number 
has  been  greatly  increased  by  diligent  researches  made  with  a 
view  to  obtain  cheaper  tanning  materials. 

We  shall  here  discuss  the  most  important  of  such  materials, 
first  mentioning  the  inspissated  vegetable  juices  which  are 
imported. 

Rutca  is  the  inspissated  juice  of  Rutca  formosa,  and  is  used 
for  tanning  only  in  the  northwest  of  India. 

Kino  is  the  inspissated  juice  of  Ptcrocarpus  erinaceus  and 
marsupium.  Numerous  varieties  of  kino  are  known  in  com- 
merce, though  the  principal  ones  are  those  coming  from  Africa 
and  Malabar.  The  African  kino,  which  is  the  best,  but  seldom 
found  in  commerce,  is  the  inspissated  juice  of  Ptcrocarpus 
erinaceus. 

The  Malabar,  or  East  Indian  kino,  is  derived  from  Pterocar- 
pus  marsupium,  a  tree  indigenous  to  Farther  India,  Malabar 
and  Ceylon.  Both  varieties  of  kino  are  very  rich  in  tannic  acid, 
that  of  the  latter  being  identical  with  gallotannic  acid,  it  yield- 
ing, on  heating,  pyrogallic  acid.  On  account  of  its  high  price, 
and  the  disagreeable  red  color  it  imparts  to  the  leather,  this 
tanning  material  is  but  little  used. 

Gambicr  is  an  extract  from  the  leaves  of  Uncaria  gambir. 
It  forms  cubical  pieces  to  \  inch  thick  of  a  light  and  dark 
rust  color  or  sometimes  gray  color,  which  float  upon  water  and 
are  very  friable.  Gambier  is  slightly  soluble  in  cold  water,  but 
readily  in  hot.    Its  percentage  of  tannin  is  quite  high. 

Catechu,  or  terra  japonica,  is  the  dry  extract  from  the  heart 

(29) 


3o 


THE  MANUFACTURE  OF  LEATHER. 


wood  of  a  mimosa,  Acacia  catechu,  growing  in  the  East  Indian 
islands.  Its  principal  constituents  are  :  Catechin,  a  brown  sub- 
stance which  can  be  precipitated  from  its  solution  with  glue, 
and  catechutannic  acid,  which  appears  to  be  formed  from  the 
catechin  by  exposure  to  the  air.  It  colors  ferric  oxide  green, 
and  gives  a  green-black  precipitate  with  ferric  salts.  The 
value  of  catechu  may  be  judged  by  its  external  color,  hard- 
ness, taste,  solubility  in  spirit  of  wine,  etc.  Genuine  catechu 
melts  upon  the  tongue,  while  non-genuine  sticks  to  it.  Adul- 
terations with  blood,  sugar,  etc.,  can  be  detected  by  the 
characteristic  odor  of  these  admixtures  when  burnt.  The 
leather  produced  with  catechu  is  not  of  a  particularly  good 
quality,  it  being  of  a  dark  color,  permeable  to  water,  spongy, 
and  at  the  same  time  hard. 

Gall-nuts  are  the  richest  in  tannin  of  all  tanning  materials. 
They  are  morbid  excrescences  of  the  leaves  and  young 
branches  of  Quercus  infectoria,  Oliv.,  formed  by  the  puncture 
of  gall-flies  (Cynips  gallce  tinctorial ,  belonging  to  the  Hymen- 
optera,  for  the  purpose  of  depositing  their  eggs.  As  the  latter 
develop,  excrescences  called  galls  or  gall-nuts  are  formed  on 
the  punctured  places  by  the  exudation  of  sap  and  enlargement 
of  the  cells.  The  larvae  which  are  inclosed  in  the  galls  are  sup- 
ported by  the  juices  of  the  plant  until  they  become  perfect 
insects,  when  they  perforate  the  gall  and  escape.  When  this 
happens  the  excrescence  loses  much  of  its  astringent  prfnciple 
and  becomes  lighter  in  color  and  finally  entirely  white,  while  if 
collected  before  the  entombed  insect  is  completely  developed, 
the  galls  are  of  a  dark  to  blackish  color,  and  much  richer  in 
tannin. 

The  latter  are  known  in  commerce  as  green  galls,  and  come 
from  Aleppo,  Smyrna  and  Mesopotamia. 

Gall-nuts  are  also  imported  from  Cypria,  Karamania,  etc., 
though  they  are  not  so  good  as  the  Aleppo  galls,  with  which 
they  are  sometimes  mixed. 

European  galls,  formed  by  the  puncture  of  other  species  of 
gall-flies  on  other  varieties  of  oaks,  are  not  so  good  as  the 


VEGETABLE  TANNING  MATERAILS. 


31 


Aleppo  galls.  They  come  from  the  Morea,  Italy,  Hungary  and 
Istria.  Gallotannic  acid  is,  as  previously  mentioned,  the  most 
accurately  known. 

Galls  (Knoppern)  formed  by  the  puncture  of  a  gall-fly 
{Cynips  quercus  calycis)  in  the  young  fruits  of  Quercus  pedun- 
culata.  They  are  principally  collected  in  Hungary,  Dalmatia 
and  Slavonia,  and  contain,  besides  a  small  quantity  of  gallic 
acid,  much  tannin  closely  resembling  gallotannic  acid.  The 
percentage  of  tannin  amounts,  according  to  Mueller,  to  as  much 
as  50  per  cent. 

Chinese  Gall-nuts  form  irregular  roundish  bulbs  of  the  size  of 
a  hazel  or  walnut,  which  inclose  the  insect.  Their  rind  is 
smooth  and  felt-like,  of  a  gray  or  reddish  color,  and  very  thin, 
and  consequently  fragile.  They  show  no  vegetable  structure, 
but  a  dense,  brilliant,  resinous  fracture,  and  are  said  to  be  de- 
rived from  a  species  of  sumach.  They  are  much  in  demand  on 
account  of  their  high  percentage  of  tannin,  which,  according  to 
Mueller,  amounts  to  as  high  as  65.5  per  cent. 

Rove. — The  article  known  by  this  name,  which  is  brought 
into  commerce  ground  and  pressed  in  bricks,  is  the  so-called 
Bassora  gall-nut,  and  is  found  in  Persia  and  Asia  Minor.  It  is 
principally  exported  by  way  of  Smyrna.  It  contains  about  27 
per  cent,  of  tannic  acid.  Mixed  with  oak  or  fir  bark,  it  is, 
according  to  Eitner,  well  adapted  for  tanning  sole  leather. 

Sumach  consists  of  comminuted  leaves,  stems  of  blossoms, 
and  branches  of  several  Rhus  species,  such  as  Rhus  coriaria,  R. 
cohnus,  R.  glabrum,  R.  canadensc,  R.  ty planum,  R.  pcntaphyllum, 
Arbutus  uva  ursi,  Cyriaria  myrtifolia. 

The  following  varieties  are  found  in  commerce: 

Sicilian  Sumach,  from  Rhus  coriaria,  is  the  most  valued.  It  is 
divided  into  two  qualities,  the  best  being  of  a  greenish-yellow 
color,  while  the  inferior  variety  is  of  a  more  rusty-yellowish 
color,  and  has  less  smell  and  less  tannic  acid. 

Italian  Sumach,  which  is  also  derived  from  Rhus  coriaria,  is 
a  dirty-green  powder.  It  is  far  inferior  in  tanning  capacity  to 
the  Sicilian  variety,  it  being  besides  frequently  adulterated  with 
sondro  leaves. 


32 


THE  MANUFACTURE  OF  LEATHER. 


Spanish  Sumach. — Three  varieties  of  this  occur  in  commerce, 
viz :  Malaya  or  Priego,  Malino,  and  Valladolid,  the  last  two 
being  of  less  value  than  the  first. 

Tyrol  Sumach,  the  odor  of  which  resembles  that  of  oak  bark, 
is  derived  from  the  leaves  and  stems  of  Rhus  cotinns.  Like 
the  Italian  and  Sicilian  sumach,  it  is  frequently  adulterated  with 
fig  leaves. 

Frencli  Sumach  {'from  Coriaria  myrtifolia). 

There  are  four  varieties  :  Fauvis,  Redoul,  Donzire,  and  Pudis 
sumach,  the  last  two  being  less  liked  than  the  others. 

The  "  Tezera"  sumach,  used  by  the  Arabs  for  tanning  mo- 
rocco leather,  is  derived  from  Rhus  pentaphyllum. 

American  sumach  is  derived  from  Rhus  canadense  and  R. 
glabrum.  Large  quantities  of  it  were  formerly  used  in  the  United 
States,  the  morocco  manufacturers  mixing  it  with  an  equal 
quantity  of  Sicilian  sumach  to  form  the  tanning  liquor,  which 
was  forced  through  the  goat  skins  by  hydrostatic  pressure. 
Sumach  is  also  used  in  tanning  patent,  enameled,  and  furniture 
leathers,  sheepskins  and  grain,  split  and  buffed  leathers. 

Swedish  Sumach  is  prepared  from  the  leaves  of  the  bear-berry 
(Arbutus  uva-ursi). 

It  is  not  yet  definitely  determined  whether  all  the  different 
varieties  of  sumach  contain  the  same  or  different  kinds  of  tan- 
nic acid,  although  the  latter  is  most  probable. 

The  tannic  acid  contained  in  the  Sicilian  sumach  is,  accord- 
ing to  Stenhouse,*  identical  with  gallotannic  acid.  In  old  sum- 
ach, the  larger  portion  of  the  tannic  acid  has  been  converted 
into  gallic  acid  and  sugar. 

Leather  prepared  with  sumach  possesses  but  little  capacity  for 
resisting  water,  and  is  therefore  principally  used  for  book-bind- 
ing, portfolios,  pocket-books,  linings,  bindings,  skivers,  etc. 

Chrome  tannage  has  however  driven  sumac  almost  entirely 
out  of  the  morocco  trade. 

Valonia  is  the  acorn-cup  of  Quercus  cegilops,  the  prickly- 
cupped  oak,  a  tree  growing  in  abundance  in  the  islands  of  the 

*  Dingl.  Polyt.  Journ.  clxv.  150. 


VEGETABLE  TANNING  MATERIALS. 


33 


Grecian  Archipelago.  The  tannic  acid  of  valonia  is  not  known 
in  a  pure  state,  as  it  always  contains  gallic  acid.  The  use  of 
valonia  has  recently  much  increased  in  Europe,  it  being  espe- 
cially employed,  mixed  with  oak  tan,  for  sole-leather  in  the 
last  two  spreadings  of  the  hides  in  the  binders.  Leather  pre- 
pared with  valonia,  is  said  to  be  harder  and  less  permeable  to 
water  than  that  made  with  oak  bark,  its  weight  being  also 
increased.  The  price  of  valonia  which  contains  a  considerable 
percentage  of  tannic  acid,  is  low  compared  with  that  of  tan, 
and  it  is  much  used  by  English  tanners. 

Divi-divi  consists  of  the  dried  pods  of  a  bush  ( Cicsalpinia 
coriaria)  indigenous  to  South  America.  Leather  tanned  with 
the  extract  becomes  very  soft  and  spongy,  and  on  exposure  to 
the  air  assumes  a  more  or  less  brown  to  brown-red  color.  The 
extract  of  the  divi-divi  pods  is  also  brought  into  commerce. 
The  tannic  acid  differs  from  the  gallotanic  acid,  and,  when 
heated,  does  not  yield,  like  the  latter,  pyrogallic  acid. 

Myrobalans,  the  dried  fruit  of  Tcrmiiialia  chcbnla,  is  princi- 
pally collected  in  India.  The  fruits  exported  by  way  of  Calcutta 
are  of  a  roundish  shape,  gray-black  color,  and  hard  and  astrin- 
gent. They  contain,  principally  in  the  husk,  a  considerable  quan- 
tity of  gallic  acid,  which,  according  co  Stenhouse,  differs  so  far 
from  gallotanic  acid  as  not  to  yield,  on  boiling  with  dilute  sul- 
phuric acid,  gallic  acid,  but  a  reddish-brown  substance  insoluble 
in  spirit  of  wine. 

Myrobalans  are  used  in  Europe  in  tanning  as  an  addition  to 
oak  bark. 

Bublah  is  the  husk  of  the  fruit  of  Acacia  bambula.  It  comes 
from  India,  and  contains  considerable  tannic  acid. 

Of  the  other  foreign  materials  containing  tannic  acid,  which, 
on  account  of  their  high  price,  etc.,  are  more  extensively  used 
in  dyeing  and  coloring  than  tanning,  we  will  mention  :  — 

Logwood,  which  is  derived  from  Hcematoxylon  campcacJiianum, 
a  Ccesalpina  growing  wild  in  Yucatan  and  some  of  the  West 
Indies. 

Fustic,  obtained  from  Morns  tinctoria.    It  contains  a  peculiar 
3 


34 


THE  MANUFACTURE  OF  LEATHER. 


tannic  acid,  moritannic  acid,  or  macherin,  which  on  heating 
yields  pyrocatechin.    It  is  only  used  for  coloring  leather. 

Weld  (Reseda  luteola)  is  a  plant  belonging  to  the  Rescdaccce, 
which  grows  wild  in  all  European  countries,  though  it  is  occa- 
sionally cultivated  in  Southern  France  and  in  Germany. 

The  following  barks  are  also  made  use  of  in  tanning,  although 
not  so  extensively  as  hemlock  and  oak  barks:  — 

Larch  bark  (Larix  Europcea) . — This  bark  yields  a  material 
relatively  poor  in  tannin.  It  contains,  according  to  Davy,  1.6 
to  2  per  cent,  of  tannic  acid.  The  bark  is  used  in  England  and 
Ireland  for  tanning  sheep-skins. 

Fir  bark  (Pinus  abies)  is  principally  used  in  Europe,  in  Aus- 
trian, Bavarian,  Hanoverian,  and  Upper  Swabian  tanneries.  It 
is  claimed  to  be  especially  adapted  for  "plumping,"  or  the  so- 
called  preparatory  swelling  and  tanning  of  hides. 

Hemlock  bark  is  obtained  from  Abies  Canadensis. 

The  bark  is  light,  has  a  somewhat  balsamic  odor,  and  a 
slightly  astringent  taste.  The  tannin  is  colored  green  by  ferric 
salts,  and  brown  by  potash  lye.  It  is  the  most  important  tan- 
ning material  of  America,  where  it  is  much  used  for  tanning 
both  sole  and  upper  leathers,  two-thirds  of  all  sole  and  upper 
leathers  produced  in  the  United  States  being  tanned  with  it. 
This  variety  of  leather  has  only  lately  been  appreciated  in  many 
portions  of  Europe,  and  our  exports  of  it  are  constantly  in- 
creasing. A  mixture  of  hemlock  bark  and  oak,  termed  "union 
tannage,"  gives  a  very  serviceable  leather. 

An  extract  of  hemlock  bark  goes  into  the  European  markets 
under  the  name  of  American  hemlock  extract,  and  it  is  also  em- 
ployed in  portions  of  this  country  where  bark  is  scarce. 

It  is  chiefly  prepared  from  thick  bark,  since  the  greatest  yield 
of  tannin  is,  according  to  Eitner,  obtained  from  the  rind,  and  not 
from  the  pulp,  an  analysis  of  the  latter  showing  7.7  per  cent,  of 
tannic  acid,  and  of  the  former  1 1.3  per  cent.,  while  the  entire 
bark  yielded  10. 1  percent. 

Oak  bark,  from  Quercus  monticola  of  Michaux,  rock  chestnut 
oak,  and  Q.  tinctoria,  the  yellow-barked  oak,  are  the  most  highly 


VEGETABLE  TANNING  MATERIALS. 


5  5 


esteemed  for  tanning  purposes  in  the  United  States.  The  best 
is  the  first-named  variety,  and  the  prime  quality  is  derived  from 
the  Blue  Ridge,  which  is  the  most  easterly  ridge  of  the  Allegheny 
Mountains.  The  principal  tanneries  using  rock  chestnut-oak 
bark  are  located  in  the  state  of  Virginia,  the  western  portions  of 
the  Carolinas,  and  in  Tennessee  ;  the  bark  in  the  latter  state  being 
derived  from  the  Cumberland  Mountains.  In  tanning  it  is  used 
unmixed,  and  gives  a  beautiful  "bloom;"  the  sole  leather  pro- 
duced with  it  being  always  in  demand  for  both  home  consump- 
tion and  for  export.  The  oak  tan  bark  of  Mendocino  county, 
California  and  of  the  upper  coast  of  that  state  is  probably  the 
finest  in  the  world  for  tanning  purposes.  The  bark  of  the  yellow- 
barked  oak  is  in  tanning  commonly  mixed  with  red-oak  bark, 
as  the  color  which  the  former  yields  when  used  alone  is  objec- 
tionable. 

The  inner  bark  of  the  Q.  tiiictoria  is  the  quercitron  of  dyers. 
The  barks  of  the  Q.  alba,  white  oak,  and  Q.  rubra,  red  oak,  are 
not  esteemed  in  tanning,  the  first  being  poor  in  tannin  and  the 
second  imparting  an  undesirable  color  to  the  leather. 

Canaigrc. — In  the  rainless  regions  of  the  southwest,  the  Az- 
tecs, Zuhis,  Pueblos,  and  later  on  the  Mexicans,  have  for  cen- 
turies been  tanning  hides  with  the  root  of  a  sour  dock  or  wild 
rhubarb,  Rumcx  hymcnoscpalus,  called  by  the  early  missionaries 
sour  cane,  "  Cana  agria,"  which  was  finally  pronounced  cah-na- 
ger,  and  spelled  canaigre. 

The  commercial  value  of  canaigre  depends  upon  its  tannic 
acid.  This  is  found  in  all  parts  of  the  plant,  its  leaves,  seeds 
and  flower  stalks,  but  mainly  in  its  roots,  of  which  it  forms  an 
average  of  about  nine  per  cent,  in  the  green  state.  Of  import- 
ance also  in  tanning  are  certain  red  and  yellow  coloring  mat- 
ters which  are  extracted  along  with  the  tannic  acid,  and  which 
affect  the  quality  of  canaigre-tanned  leather.  As  much  as  three 
per  cent,  of  starch  is  also  found.  This  is  an  undesirable  con- 
stituent, causing  trouble  in  the  tanneries  unless  it  is  removed  by 
a  suitable  process  of  extraction.  The  roots  contain  an  average 
of  about  70  per  cent,  of  water,  more  or  less,  according  to  the 
age  of  the  plant  and  the  abundance  of  water  supply. 


36 


THE  MANUFACTURE  OF  LEATHER. 


The  amount  of  tannic  acid  varies  much  with  conditions  of 
growth.  Adverse  environment  seems  to  be  associated  with  the 
largest  percentage,  while  well-irrigated  roots,  grown  in  rich  soil, 
show  a  distinct  decrease.  The  lighter  color  of  cultivated  roots, 
however,  is  said  to  be  preferred  by  tanners.  During  the  annual 
period  of  growth  the  tannins  seem  to  increase  most  rapidly  at 
the  beginning  of  summer,  when  the  plant  is  dying  back  to  the 
ground.  It  appears  that  at  this  time  the  astringent  sap  of  the 
leaves  retreats  into  the  roots,  contributing  materially  to  their 
percentage  of  tannic  acid. 

Professor  Forbes  says : 

"  As  regards  the  value  of  canaigre  tanning  materials,  the 
earlier  favorable  opinions  of  tanning  chemists  have  been  excel- 
lently supported  by  the  experience  of  the  trade.  From  various 
sources  it  is  learned  that  canaigre  chips  and  extracts  have  been 
successfully  employed  either  alone  or  in  connection  with  other 
tanning  materials  for  the  production  of  a  remarkable  variety  of 
leathers,  including  both  heavier  and  lighter  grades.  According 
to  the  statement  of  different  tanners,  it  is  employed  in  the  pro- 
duction of : 

"I.  Patent  and  enameled  leather  for  the  carriage,  saddlery 
and  upholstery  trades. 

"2.  Patent  and  enameled  leather  for  fine  shoes. 

"3.  Carriage  covers  and  dashboard  leather. 

"4.  High  grade  of  carriage  and  furniture  leather  and  a  fair 
grade  of  patent  shoe  tipping. 

"  5.  Upper,  grain,  or  similar  light  leather. 

"  6.  East  India  kips  finished  as  waxed  leather. 

"  7.  Yellow  for  mittens,  horse  hides,  butts,  kangaroo,  glazed 
kid,  and  other  fine  shoe  leather. 

"  8.  The  heaviest  sole  and  harness  leather,  and  the  lightest 
calf  and  sheep,  with  best  results  for  all  kinds."  . 

Quebracho  is  a  Spanish  word  meaning  axe-breaker,  from  the 
toughness  of  the  tree,  which  breaks  the  sharpest  axes.  It  is  a 
tree  which  grows  only  in  Gran  Chaco  in  the  Argentine  Republic. 
Two  species  are  known,  the  Quebracho  bianco,  which  is  only 


VEGETABLE  TANNING  MATERIALS. 


37 


used  for  building  purposes,  and  Quebracho  Colorado,  or  red  wood. 
It  varies  in  color  from  gray  to  dark,  which  depends  entirely 
upon  the  tanning  and  coloring  matter  which  it  contains. 

The  material  is  too  strong  in  tannin,  possessing  insufficient 
non-tanning  proprieties  to  yield  well-nourished  leather  unless 
combined  with  agents  which  are  stronger  in  non-tanning  sub- 
stances. 

The  discovery  of  the  valuable  tanning  properties  of  this  wood 
is  due  to  Mr.  George  Fahr  of  Pirmasens  in  Bavaria,  who  on  a 
visit  to  the  Paris  Exposition  of  1867  saw  quebracho  wood  from 
Gran  Chaco  exhibited  as  a  dye-wood.  He  had  it  analyzed  in 
Vienna  and  found  that  it  contained  22  per  cent,  of  tannin  and  8 
per  cent,  of  coloring  matter.  This  led  him  to  import  some  of 
the  wood.  Later  analyses  were  equally  favorable,  and  in  1871 
several  firms  in  Havre  and  Antwerp  imported  considerable  quan- 
tities of  the  wood.  Mr.  Fahr  and  his  brothers  then  got  up  machin- 
ery to  rasp  the  wood,  and  by  1876  were  enabled  to  furnish  con- 
siderable quantities  of  quebracho  chips  to  Alsatian,  Rhenish  and 
Swiss  tanners.  But  through  the  improved  tannage  obtained  by 
using  quebracho  wood  Messrs.  Fahr  found  their  leather  in  such 
demand  that  they  were  compelled  to  give  up  the  supplying  of 
quebracho  wood  to  other  tanners,  as  they  used  all  they  could 
produce  in  their  own  tannery.  Tanneries  in  Argentina  also  kept 
pace  in  tanning  with  quebracho,  and  the  primitive  tanneries  of 
that  country  soon  grew  into  enormous  establishments.  As  their 
hides  and  tanning  material  were  at  hand  and  cheap,  they  quickly 
obtained  European  markets  for  their  leather,  which  markets 
were  needed  to  prevent  overproduction  in  a  country  that  only 
offered  poor  markets  for  them.  The  leather  made  with  que- 
bracho is  superior  both  in  firmness  and  color. 

The  quebracho  tree  of  Gran  Chaco  is  about  18  to  36  feet  in 
height  and  has  a  diameter  of  18  to  40  inches.  When  first  felled 
the  color  is  a  light  yellow  but  on  exposure  it  turns  to  a  light  red. 

The  best  wood  comes  from  Vera,  three  days  journey  from 
Buenos  Ayres  on  the  railroad  leading  from  Santa  Fe  to  Garabato, 
where  virgin  forests  are  found  along  the  Parana  and  the  Picole- 


38 


THE  MANUFACTURE  OF  LEATHER. 


majo  rivers.  It  is  said  that  when  quebracho  wood  is  of  good 
quality  and  freshly  rasped  it  retains  much  natural  moisture  so 
that  it  will  ball  up  in  the  hand.  This  moisture  is  said  to  be  due 
to  the  quantity  of  tannin  it  contains,  and  which  when  first  felled 
oozes  from  the  cut  surface  like  resin. 

At  a  convention  of  German  tanners  held  in  Hamburg,  Pro- 
fessor Eitner  in  his  speech  made  some  interesting  remarks  on 
the  uses  of  quebracho. 

The  speaker  said  that  the  advantages  of  the  quebracho  wood 
consisted  not  only  in  making  the  tanning  cheaper  on  account  of 
the  low  price  of  the  material  and  the  obtaining  of  a  larger  out- 
put, but  also  on  account  of  effecting  rapidly  a  thorough  tanning 
especially  for  certain  kinds  of  leather ;  and  a  splendid  product 
can  be  obtained  by  the  addition  of  quebracho  wood  to  the  liquor. 

"All  tanning  matter,"  said  the  speaker,  "contains,  if  I  may 
so  express  myself,  three  different  kinds  of  tanning  material,  to 
wit.,  one  pale  and  readily  soluble,  which  penetrates  the  hide  very 
easily  and  impregnates  the  fibre  itself ;  a  darker  one  a  little  less 
soluble,  which  also  enters  the  hide  easily  and  is  fixed  to  the  ex- 
terior part  of  the  fibre  ;  and  one  almost  insoluble,  which  only  en- 
ters the  hide  by  violent  means  and  which  makes  the  leather  dark 
colored  and  of  a  disagreeable  appearance. 

"  Now,  it  is  in  the  wood  of  quebracho  that  the  first  of  these 
tanning  substances  is  found  in  large  quantities,  and  explains  the 
fact  that  the  pale  liquor  of  quebracho  wood  penetrates  so  easily 
into  the  hide,  more  readily  even  than  sumach.  And  it  is  this 
quality  that  renders  quebracho  particularly  valuable  to  the 
tanner. 

"  If  the  quebracho  is  not  qualified  to  furnish  a  solid  leather 
in  the  ordinary  process  of  tanning — if  the  leather  tanned  with 
this  substance  fails  in  some  qualities — it  is  on  the  contrary  par- 
ticularly adapted  to  tan  the  hide  promptly  and  thoroughly,  and 
to  render  it  proper  for  the  absorption  of  strong  liquor,  that  is  to 
say,  the  thickest." 

To  obtain  a  solid  and  completely  saturated  leather  the 
speaker  recommends  a  mixture  of  quebracho  and  oak  bark  as 


VEGETABLE  TANNING  MATERIALS. 


39 


being  practically  efficient.  "  Oak  bark,"  said  he,  in  substance, 
"  is  not  the  enemy  of  quebracho  wood  ;  as  the  two  tanning  sub- 
stances can  be  used  together.  By  adding  to  the  oak  bark  some 
quebracho  wood  the  expense  of  the  tanning  is  decreased  and 
leather  is  obtained  which  in  quality  and  appearance  is  the  equal 
of  that  tanned  with  pure  oak  liquor.  Good  results  may  also  be 
had  by  mixing  other  kinds  of  tannin  with  the  quebracho,  which 
is  of  benefit  to  the  small  tanner." 

A  sample  of  leather  tanned  with  quebracho  extract  will  be 
found  with  the  other  samples  at  the  end  of  this  book.  It  is 
furnished  by  A.  Klipstein  &  Co.,  who  are  the  pioneers  in  que- 
bracho in  this  country  and  the  chief  importers,  handling  as  they 
do  the  output  of  the  principal  factories  of  the  world  furnished 
for  American  consumption. 

Quebracho  is  especially  interesting  because  of  its  adding 
weight  and  firmness  to  leather,  and  also  because  it  furnishes 
light  leather,  which  is  excellently  well  adapted  for  the  taking 
of  all  sorts  of  dyes;  and  heavy  leathers  of  all  kinds  of  excel- 
lent quality. 

A.  Klipstein  &  Co.'s  head  office  is  in  New  York,  and  their 
branch  offices  are  in  Philadelphia,  Boston,  Chicago,  Providence, 
Cincinnati,  and  Hamilton,  Ont.,  where  stock  is  carried  and  full 
information  furnished  as  desired. 

A.  Klipstein  &  Co.  have  issued  a  little  pamphlet  descriptive 
of  the  qualities  and  use  of  quebracho.  It  is  interesting  as 
showing  the  extent  of  the  sale  of  this  tanning  material  and  its 
utility  for  the  purpose  intended.  They  give  the  analysis  of  the 
quebracho  from  a  tract  of  land  at  Gran  Chaco,  as  follows  : 


Tannic  acid   28.20 

Foreign  substances   1.70 

Extract  ashes   0.40 

Water   11.85 

Insoluble  parts   57-85 


100.00 

For  some  years  past  quebracho  has  been  employed  in  every 


40 


THE  MANUFACTURE  OF  LEATHER. 


European  tannery  with  success,  and  the  following  figures  will 
show  that  within  the  last  four  years  the  exports  from  the  Ar- 
gentine Republic  to  Europe  have  rapidly  increased,  as  follows: 

1892   29,700  tons. 

1893   49.4°°  " 

1894   54.540  " 

1895   154,000  " 

Of  all  European  countries,  Germany  has  become  the  largest 
consumer,  having  used  it  chiefly  for  sole  leather.  The  result 
has  been  the  almost  total  destruction  of  the  American  export 
trade  in  sole  leather  to  Germany,  as  may  be  seen  from  the 
U.  S.  Treasury  reports  as  follows : 

Sole  Leather  Exported  to  Germany  from  the  United  States  from 
1876  to  1896. 
Pounds. 


876   6,400,000 

877   6,ioo,coo 

878   7,100,000 

879   7,500,000 

880   3,900,000 

881   3,600,000 

882   2,500,000 

883   2,400,000 

884   2,500,000 

885   3,000,000 

886   2,000,000 


Pounds. 

1887   1,900,000 

1888   1,800,000 

1889   i,6oo,oco 

1890   1,700,000 

1 89 1   1,400,000 

1 892   81 6,000 

1893     548,000 

1894   542,000 

1895   733»O0° 

1 896*   1 86,000 


*  For  10  months. 


The  quebracho  tree  grows  in  the  large  forests  known  as  Gran 
Chaco,  situated  in  the  northern  part  of  the  Argentine  Republic. 
The  logs,  which  are  employed  for  tanning  purposes  only,  are 
used  without  the  bark  and  run  from  5  to  10  meters  in  length 
with  a  diameter  of  from  50  to  100  centimeters.  The  best  wood 
grows  north  of  Vera  Station  on  the  railway  line  from  Santa  Fe 
to  the  Gran  Chaco  (Garabato).  These  forests  extend  in  the 
north  as  far  as  the  river  Bermejo,  and  in  the  east  as  far  as  the 
river  Parana. 

There  are  also  some  small  forests  situated  on  the  opposite 


VEGETABLE  TANNING  MATERIALS. 


41 


shore  of  the  river  Parana,  in  the  Province  of  Corrientes,  and 
some  in  the  west  as  far  as  the  Provinces  of  Salta  and  Santiago 
del  Estero. 

The  soil  of  the  surrounding  provinces  is  unfit  for  the  growth 
of  quebracho,  and  the  trees  found  in  the  districts  of  Corrientes 
(Empedrado)  and  Satiago  del  Estero,  are  small  and  poor,  which 
accounts  for  the  bad  quality  of  the  quebracho  coming  from  these 
provinces,  while  the  Gran  Chaco  product,  on  the  contrary  shows 
far  stronger  tanning  proprieties  combined  with  a  lighter  color. 
Tanners  will  understand  the  importance  of  always  using  the 
better  quality  of  quebracho  when  they  know  that  the  inferior  and 
cheaper  kind,  besides  containing  far  less  tannic  acid,  is  also  full 
of  a  peculiar  dye-stuff  which  gives  the  leather  a  dirty  color  and 
decreases  its  weight,  while  pure  Gran  Chaco  wood  gives  the 
leather  a  clear  light  yellow  tint,  and  considerably  increases  its 
weight. 

The  advantage  in  the  use  of  quebracho  lies  in  the  fact  that  the 
tanning  process  is  rendered  much  cheaper,  owing  to  the  low 
price  of  the  tanning  material  and  the  better  results  obtained. 
Besides,  the  process  is  more  rapid  and  the  tanner  is  enabled  to 
obtain  by  it  good  leather  of  various  kinds. 

The  best  results  are  obtained  by  mixing  quebracho  with  other 
tanning  materials,  and  the  German  tanners  have  successfully 
employed  a  mixture  of  quebracho  and  oak  or  fir  bark. 

Different  tanning  materials,  such  as  hemlock,  gambier,  can- 
aigre,  oak  or  fir  mixed  with  quebracho,  give  the  very  best  re- 
sults, and  the  use  of  quebracho  considerably  reduces  the  expense 
of  tanning  sole  and  upper  leather. 

Those  who  have  carefully  tested  quebracho  are  now  steady 
consumers  of  it,  and  are  fully  satisfied  as  to  its  good  properties. 

The  following  process  is  given  for  using  pure  quebracho 
wood  for  sole  leather  in  Buenos  Ayres,  taking  as  an  illustration 
30  cow  hides : 

First  or  coloring  liquor. — The  hides  are  first  treated  with 
some  partially  exhausted  liquor  4  to  6  degrees  in  strength.  If 
there  is  no  such  liquor  employ  clear  water  with  quebracho  of 


42 


THE  MANUFACTURE  OF  LEATHER. 


the  strength  above  mentioned,  then  handle  about  four  times 
until  an  even  color  is  obtained.  Much  attention  should  be 
given  to  the  first  liquor  so  that  the  leather  receive  a  light  color. 
Should  the  liquor  be  cloudy  use  a  little  alum-water  to  clear. 

Second  Liquor. — For  30  cow  hides  put  180  kilos,  quebracho 
chips  in  vat  with  fresh  water  and  handle  the  hides  several  times 
for  a  couple  of  days.  Take  out  the  used  wood  and  put  in  some 
180  kilos,  more,  then  handle  twice  a  day  until  all  the  tannin  is 
extracted  from  the  wood,  probably  in  about  four  days. 

Third  Liquor. — Put  200  kilos,  quebracho  in  vat  with  fresh 
water,  handle  the  hides  in  this  once  a  day  for  six  to  eight  days, 
when  they  will  be  ready  for  laying  away. 

At  the  laying  away  hides  receive  about  26  kilos,  quebracho 
per  hide  on  the  grain  side.  When  the  vat  is  filled  add  the  liquor 
from  the  spent  wood  out  of  former  steeping  and  let  the  hides 
rest  25  to  30  days.  After  this  take  the  leather  out  of  the  vat, 
rinse  it  well  in  previously  used  liquor,  and  let  it  run  dry  without 
liquor  or  water  in  the  washwheel. 

About  half  an  hour  will  suffice  to  make  the  leather  pliable. 
To  work  it  on  the  table  give  it  a  good  washing  with  water  and 
sulphuric  acid,  then  dry  and  roll  the  leather  carefully. 

Hides  worked  in  this  way  show  a  bright  clear  yellow  color 
and  good  weight,  and  are  quickly  tanned. 

Method  for  employing  quebracho  with  oak  bark  for  sole  leather 
in  Europe,  as  recommended  by  Mr.  Eitner  at  the  Tanners'  Con- 
vention in  Hamburg: — 

In  the  manufacture  of  heavy  sole  leather,  which  presents  the 
greatest  resistance  to  the  absorption  of  the  liquor,  the  following 
method  is  recommended  for  an  ordinary  pack : 

During  the  swelling  it  is  not  only  important  that  the  acid  of 
the  liquor  should  preponderate,  but  also  that  it  should  be  pure 
and  free  from  all  injurious  fermenting  substances.  The  hides 
should  be  left  in  soak  24  to  28  hours — then  rinsed  and  replaced 
so  as  to  be  in  proper  condition  for  the  liquor.  While  in  the  first 
and  second  liquor  they  are  treated  to  a  mixture  of  7^  kilos, 
of  quebracho  and  an  equal  quantity  of  oak  bark ;   if  a  third 


VEGETABLE  TANNING  MATERIALS. 


43 


liquor  is  necessary  use  a  mixture  of  60  parts  of  quebracho  to 
40  parts  of  oak  bark,  and  leave  them  in  the  liquor  for  about 
20  days.  By  this  repeated  and  prolonged  immersion  the  time 
employed  for  tanning  is  considerably  shortened. 

At  the  first  laying  away  the  hides  will  receive  20  kilos,  of 
powdered  matter,  consisting  of  60  parts  quebracho  to  40  of 
oak  bark ;  on  the  second  laying  away  a  larger  proportion  of 
quebracho  may  be  employed.  Time  of  immersion  about  the 
same — about  20  days. 

The  washing  is  done  with  the  spent  liquor  obtained  from  the 
previous  operations. 

The  feature  in  the  sole  leather  situation  in  the  United  States 
since  the  bank-panic  of  1893  has  been  the  growing  call  for 
cheap  stock,  this  being  true  not  only  in  regard  to  sole  leather, 
but  consumers  seem  to  demand  cheapness  in  nearly  all  kinds 
of  leather.  This  must  tend  to  an  increase  in  the  consumption 
of  tropical  tanning  materials  used  in  connection  with  the  old 
fashioned  bark  liquors.  The  growing  importation  of  foreign 
tanning  material  has  had  the  effect  of  considerably  cheapening 
domestic  oak  bark.  Oak-tanned  leather  can  be  produced  at 
less  cost  to-day  than  ever  before. 

However,  even  where  oak  bark  is  used,  the  desired  results, 
i.  e.,  cheapness  and  rapidity,  can  only  be  attained  with  concen- 
trated liquors,  and  soon,  no  doubt,  a  tannery  not  furnished  with 
an  extract  plant  and  not  using  extracts  such  as  are  to  be  had  in 
the  market,  to  strengthen  and  also  to  cheapen  the  liquors,  will 
be  the  exception. 

Whether  the  production  of  quebracho-tanned  sole  leather 
will  continue  to  increase  at  the  present  rate  in  Germany  is  a 
question  hard  to  answer.  The  enlargement  of  the  tanneries 
making  this  class  of  leather  now  in  operation,  and  the  number 
of  new  yards,  either  completed  or  in  course  of  construction,  are 
meanwhile  amply  sufficient  to  supply  the  present  demand. 

The  United  States  has  lost  its  export  trade  in  sole  leather  to 
Germany  through  the  introduction  of  quebracho-tanning  in  that 
country,  and  probably  other  loss  of  trade  with  other  countries 
will  follow  from  similar  causes. 


44 


THE  MANUFACTURE  OF  LEATHER. 


The  importance  to  the  leather  producer  of  keeping  himself 
fully  posted  on  what  is  going  on  around  him,  can  hardly  be 
over-estimated.  It  is  if  possible  even  more  essential  that  he 
should  do  so,  than  is  the  necessity  of  giving  the  closest  attention 
to  the  department  of  his  business  involving  the  purchase  of  raw 
material  and  sale  of  the  finished  product. 

Quebracho  is  cheaper  than  oak  bark  and  costs  but  little  more 
than  hemlock.  Quebracho,  however,  is  claimed  to  lack  some 
of  the  important  non-tanning  constituents  of  other  tanning  ma- 
terials which  "  nourish  "  the  leather  and  serve  to  acidify  the 
tan-liquors  while  effecting  no  actual  change  on  the  organic  tis- 
sue of  the  leather.  It  should  therefore  be  used  only  in  con- 
junction with  other  tanning  materials,  richer  in  non-tanning 
matter.  The  red  quebracho  contains  a  large  proportion  of  red 
coloring  matter,  easily  soluble  in  warm  water,  although  vigor- 
ously resisting  the  action  of  cold.  Consequently,  proper  pre- 
cautions must  be  observed,  or  the  leather  will  have  a  reddish 
tinge.  Leather  tanned  with  quebracho  alone  has  no  specially 
distinctive  color.  If  alum  and  salt  are  added,  finer  results  even 
are  attained  than  with  gambier.  Quebracho,  alum  and  salt  pro- 
duce a  handsome  pale  straw-colored  grain,  leaving  the  flesh-side 
almost  white.  Several  large  establishments  in  Germany  are 
devoted  to  the  manufacture  of  quebracho  extract,  notably  two 
in  the  vicinity  of  Hamburg,  and  one  near  Frankfort.  The  ex- 
tract is  put  up  in  crystallized  form,  containing  65  to  70  per 
cent,  tannin,  or  as  a  soft  paste  containing  about  45  per  cent. 

Palmetto  root. — Palmetto  root  is  found  abundantly  in  Florida, 
and  also  grows  in  Alabama  and  Louisiana.  There  is  some  in 
Tennessee.  It  shows  10  per  cent,  of  tannin.  The  root  can  be 
cut  up  like  bark.  The  tannin  produces  tough  grain,  and  strong 
durable  leather.  Its  action  is  rapid.  Palmetto  has  long  been 
studied  in  regard  to  tanning.  It  tans  rapidly,  giving  pleasing 
light  color,  toughness  and  pliability,  and  is  a  good  filler  of 
leather. 

It  has  attracted  much  attention  of  late  years  in  the  south, 
a  tannery  using  this  material  having  been  in  operation  at 


VEGETABLE  TANNING  MATERIALS. 


45 


Sanford,  Fla.,  for  some  time.  Palmetto  is  a  comparatively  new 
material  to  leather  manufacturers.  Its  merits  will  no  doubt  be 
fairly  tested  particularly  when  offered  for  sale  in  the  convenient 
form  of  extract. 

Chestnut  oak  wood  is  also  for  tanning ;  it  is  prepared  in  the 
form  of  an  extract  and  is  fully  described  in  Chapter  V. 

Walnut  bark  from  Juglans  regia  gives  a  very  soft  leather,  but 
can  only  be  otained  in  small  quantities, 

Lombardy  poplar  bark  gives  a  light-brown  leather  with  an  odor 
resembling  that  of  Russia  leather. 

Elm  bark  from  Ulmus  campcstris,  is  especially  used  in  Nor- 
way for  manufacturing  the  beautiful  Norwegian  glove  leather. 

Horse-chestnut  bark,  from  sEsculiis  hippocastanum.  The  bark 
of  this  tree  contains  a  tannin  which  is  colored  intensely  green  by 
ferric  oxide.  Besides  the  tannin,  which  is  also  found  in  other 
parts  of  the  tree,  the  bark  contains  fraxin,  fraxetin,  aesculin, 
aesculetin,  and  aesculetin  hydrate,  a  small  quantity  of  a  peculiarly 
yellow  crystalline  body  and  a  pectine  substance  which  is  de- 
composed into  formic  acid,  oxalic  acid,  and  protocatechuic  acid 
by  boiling  potash.  The  leaves  of  the  horse  chestnut*  contain 
also  tannic  acid,  wax,  a  variety  of  resin  (C.iGH.nOn)  and  a  resin- 
ous substance  (C17H,sO;)  possessing  a  peculiar  odor  of  frankin- 
cense. The  young  leaves  and  buds  contain  a  peculiar  tannin 
to  which  Rochleder  has  applied  the  term  " phyllocitannic  acid." 

ALsculotannic  Acid.\ — Different  kinds  of  tannic  acid  are  found 
in  the  horse-chestnut,  aesculotannic  acid  (C^H^O,,)  occurring, 
according  to  Rochleder,  in  the  bark,  leaves,  flower-buds,  ripe 
and  unripe  seeds,  roots,  and  the  trunk.  In  a  pure  state  it  forms 
an  almost  colorless  amorphous  powder  readily  soluble  in  water, 
spirit  of  wine  and  ether.  By  the  action  of  the  air  and  an  alkali, 
or  substances  containing  oxygen,  such  as  chromic  acid,  it  is  de- 
composed into  a  brown  body  having  the  constitution  C,f,H,2013. 
Fusing  with  potash  changes  zesculotannic  acid  into  phloroglucin 
and  proto-catechuic  acid.  Ferric  chloride  colors  the  tannic 
acid  green. 

*  Rochleder  Wiener  Akadem.,  24  to  48;  236  to  254;  604;  607  to  657. 
t  Ibid.,  liv.  607. 


46 


THE  MANUFACTURE  OF  LEATHER. 


An  aqueous  extract  of  the  bark  comes  into  commerce  under 
the  name  of  "  horse-chestnut  extract!'  The  percentage  of  tannic 
acid  in  the  extract  varies  according  to  its  specific  gravity.  It 
is  at  present  much  used  in  Germany  and  other  portions  of  Eu- 
rope as  an  addition  in  oak-bark  tanning,  and  is  said  to  give 
good  leather.  It  is  considerably  cheaper  than  quercotannic  acid. 

Willow  Bark. — The  following  are  the  principal  willow  barks 
used  in  tanning  ;  Salix  alba,  S.  arenaria,  S.  fragilis,  S. purpurea, 
etc.  There  is  not  much  difference  in  the  value  of  the  barks, 
though  it  is  claimed  that  barks  containing  salicin,  as  for  instance 
that  of  S.  purpurea,  are  not  so  good  as  others.  The  amount  of 
tannin  varies  from  6  to  1 6  per  cent.  In  Russia  willow  bark  is 
used  for  tanning  Russia  leather,  and  in  Sweden  and  Norway  for 
preparing  the  well-known  Swedish  glove  leather.  The  tannic 
acid  contained  in  willow  bark  colors  ferric  salts  green,  and,  when 
treated  with  dilute  sulphuric  acid,  yields  sugar  and  possibly 
gallic  acid,  though  this  is  doubtful. 

Alder  Bark  contains  a  high  percentage  of  tannin,  amounting, 
according  to  Gassincourt,  to  36  per  cent. 

Beech  bark  from  Fagus  silvatica  mixed  with  oak  bark  may  be 
used  as  a  substitute  for  the  latter,  but  the  resulting  product  is  of 
an  inferior  quality.  It  contains  according  to  Davy,  2  per  cent, 
of  tannin,  and  besides  a  peculiarly  red  matter  and  a  substance 
with  an  odor  of  vanilla. 

Protacecz  Barks. — The  trees  from  which  this  tanning  material 
is  obtained  are  indigenous  to  the  Cape  and  Australia.  The 
principal  ones  are  the  Protca  cajiocarpa  (knotted  tree)  and 
Banksia  serrata.  The  tannin  of  the  latter  imparts  a  beautiful 
violet-blue  color  to  solutions  of  ferric  salts,  while  that  of  the 
first  colors  iron  green.   Both  give  a  brown  color  with  potash  lye. 

Snouba  Bark. — The  Aleppo  fir  (Piuus  halcpcnsis)  yields  two 
important  tanning  matarials,  namely  the  snouba  bark,  and  the 
scorza  rosa.  The  first  is  the  inner  bark  of  the  tree  freed  entirely 
from  the  rind,  and  comes  from  Tunis  and  Algiers. 

The  scorza  rosa  is  the  rind  of  the  same  tree,  obtained  in 
Southern  Italy,  and  especially  in  Sicily,  from  the  living  trees  in 


VEGETABLE  TANNING  MATERIALS. 


47 


a  very  rational  manner,  so  that  the  flesh  of  the  bark  remains 
intact,  and  produces,  like  the  cork  tree,  new  bark,  which  is  per- 
iodically taken  off.  Snouba  bark  contains  2$  per  cent,  of  tannin, 
and  scorza  rosa  13  to  15  per  cent.  The  tannin  colors  ferric 
salts  green,  while  it  becomes  brown  by  an  addition  of  potash 
lye. 

Ratanhy  root  is  obtained  from  Krameria  triandra,  which 
grows  in  Peru.  The  root  comes  into  commerce  in  a  commi- 
nuted state,  and  is  very  rich  in  tannin,  which  is  extracted  with 
water,  and  the  resulting  solution  used  as  an  addition  in  tanning. 
The  proportion  of  tannin  is,  according  to  Peschir,  as  much  as 
42.6  per  cent.  It  corresponds,  according  to  A.  Rabe,*  with  the 
formula  C20H20O9.  It  is  not  a  glucoside,  and  passes,  by  the 
splitting  off  of  H20,  over  into  ratanhy  red  C.2nHIgOH. 

Ai>ens  root,  from  Geum  urbanutn,  contains,  according  to 
Trommsdorff,  up  to  41  per  cent,  of  tannin.  Solutions  of  it  have 
occasionally  been  used  as  an  addition  in  tanning. 

Tormentil  root  and  Sassafras  root  show  a  still  higher  percent- 
age of  tannin,  the  first  containing,  according  to  Gassincourt,  46 
per  cent,  of  it,  and,  according  to  Reinsch,  up  to  58  per  cent. 
Both  roots  being  very  expensive  are  not  often  used  for  tanning. 

Geranium  wallichianum  is  a  new  tanning  material  which 
grows  in  India  and  contains  about  25  percent,  tannin.  Leather 
tanned  with  it  greatly  resembles  that  tanned  with  canaigre,  it 
being  only  somewhat  darker. 

The  wood  of  the  Algarobia  glandulosa  of  Gray,  niesquite  oak, 
and  Qucrcus  virens,  live  oak,  contains  much  tannin  in  its  entire 
mass,  and  is  very  successfully  used  in  America  in  place  of  tan. 

Mimosa. — Besides  the  foregoing,  the  following  tannins  have 
been  proposed  and  occasionally  used :  Barks  of  Bntca  frontosa 
and  Butca  gibsonis,  both  indigenous  to  the  West  Indies  ;  fruits 
of  Balsomokarpon  brevifolium\,  bark  of  Eucalyptus;  Pangitc,  a 
root  growing  in  India;  Pimica  granatum,  etc. 

In  Chapters  XII  and  XIII,  we  shall  discuss  the  mineral  tan- 
ning substances. 

*Pharm.  Zeitung  f.  Russland,  xix.  577. 

t  Engl.  Patentberichte,  1875,  Ramsbacher,  Masurer. 


CHAPTER  IV. 


LEACHING;  THE  BARKOMETER  ;  BARK  MILLS;  BARK  CONVEYER ; 

THE  TAN  PRESS. 

The  present  generation  need  fear  no  scarcity  of  hemlock  or  oak 
bark.  The  question  of  the  day,  in  the  struggle  for  economical  re- 
sults in  the  tanning  industry,  is  leaching.  Many  tanners  delude 
themselves  with  the  idea  that  they  are  getting  the  best  results 
possible  considering  the  conditions  under  which  they  are  work- 
ing, and  by  an  occasional  analysis  of  their  spent  tan  they  ap- 
parently prove  their  position. 

The  results  to  be  obtained  must  be  admitted  to  consist  in  the 
extraction  of  a  maximum  amount  of  tannin  with  a  minimum 
amount  of  water.  It  therefore  does  not  follow  that  when  the 
exhausted  bark  shows  only  one  per  cent  of  tannin,  which  is 
considered  a  good  result,  that  the  tannin  taken  out  has  been 
secured  economically. 

There  are  at  least  four  cardinal  points  to  be  considered  in 
leaching,  viz;  1st,  the  character  of  the  material  to  be  treated; 
2d,  a  proper  division  to  secure  the  best  results  ;  3d,  the  temper- 
ature and  quantity  of  water;  and  4th,  the  proper  handling  of 
the  liquor.  In  addition  to  these  are  the  minor  questions  of  the 
shape  and  size  of  the  leach,  the  handling  and  wetting  of  the 
bark,  forced  or  gravity  leaching  and  many  other  points. 

Many  elaborate  and  expensive  systems  of  forced  leaching 
have  been  tried,  and  fairly  good  results  have  been  obtained  by 
these  methods — upward  flow  and  downward  flow,  and  all  the 
other  modifications  that  impractical  ingenuity  could  devise. 

The  more  elaborate  and  expensive  the  system  and  the  more 
patents  and  secrecy  surrounding  it,  the  better  the  results  have 
been  supposed  to  be. 

(48) 


LEACHING. 


49 


It  may  be  assumed  that  a  system  best  for  oak  bark  might  not 
be  the  best  one  for  hemlock  or  canaigre.  Yet  there  are  cer- 
tain general  principles  applicable  to  all  which  may  be  modified 
to  suit  the  material  to  be  treated,  and  the  results  are  largely 
dependent  on  the  skill  and  reasoning  faculty  of  the  operator. 

As  a  rule  only  one  general  system  is  employed  by  American 
tanners  and  extract  makers  and  that  is  the  gravity  system.  To 
advocate  any  other  system,  such  as  modifications  of  the  diffusion 
process,  involving  the  expenditure  of  large  sums  to  violate  the 
laws  of  nature,  would  necessitate  the  rebuilding  of  99  per  cent, 
of  the  leach  houses  in  America  ;  therefore,  attention  will  be  paid 
to  securing  the  best  results  under  the  system  generally  employed, 
involving  as  few  changes  in  arrangement  as  possible. 

A  man  must  fully  understand  what  he  has  to  do  before  he 
can  determine  the  best  way  to  do  it.  In  the  case  of  leaching 
we  will  assume  an  extreme  condition  to  make  the  subject  plainer. 
Suppose  the  bark,  instead  of  being  prepared  in  the  usual  way, 
is  cut  in  pieces  one  inch  thick  and  two  inches  square.  It  will 
be  readily  seen  that  if  cold  water  is  pumped  on  top  and  at  the 
same  time  removed  from  the  bottom,  passing  rapidly  among 
and  not  through  the  pieces  of  bark,  an  immense  quantity  of 
water  will  be  handled  and  yet  the  bark  will  practically  never 
be  exhausted.  This  is  an  extreme  illustration  of  the  most  com- 
mon way  of  leaching. 

What  we  must  do  is  to  pass  the  water  through  the  bark  and 
not  around  it.  We  must  regulate  the  temperature  so  as  to  se- 
cure the  greatest  solvency,  therefore  we  grind  or  cut  the  bark 
and  warm  the  water.  Still,  no  matter  how  fine  the  bark  or  how 
hot  the  water,  if  the  operation  is  rapid  the  solvent  passes  around 
the  particles  of  bark  and  not  through  them  ;  therefore,  slow 
leaching  is  absolutly  necessary  to  secure  maximum  density  in 
the  liquor. 

If  we  have  a  leach  filled  with  dry  bark  and  water,  or  weak 
liquor  is  pumped  on  it,  it  at  once  goes  to  the  bottom  and  does 
not  dissolve  or  take  up  the  tannin  in  the  bark  above  it.  This 
is  another  method  of  forcing  the  liquor  around  the  bark  instead 
4 


THE  MANUFACTURE  OF  LEATHER. 


of  through  it ;  therefore,  a  leach  whe  n  once  filled  with  liquor 
should  never  be  allowed  to  become  dry  or  out  of  the  liquor  on 
top.  There  is  a  loss  to  be  incurred  in  extreme  slow  leaching. 
The  point  of  saturation  must  not  be  overlooked.  A  gallon  of 
water  at  6o°  Fah.  will  hold  in  solution  a  definite  quantity  of 
tannin,  sugar,  salt,  or  other  soluble  matter  and  no  more.  At  a 
higher  temperature  its  solvent  power  is  generally  increased,  but 
on  cooling  again  the  excess  is  thrown  out  of  solution.  Tannin 
and  the  other  soluble  principles  of  bark  are  heavier  than  water 
as  shown  by  the  barkomcter  or  hydrometer. 

If  we  fill  a  leach  with  fresh  bark  properly  prepared  and  then 
let  in  warm  water  and  allow  it  to  stand  undisturbed  for  forty- 
eight  hours — although  at  the  beginning  the  conditions  through- 
out the  leach  were  uniform — we  will  find  after  this  maceration, 
or  soaking,  that  both  the  liquor  and  chips  at  the  bottom  of  the 
leach  are  stronger  than  the  liquor  and  chips  at  the  top  of  the 
same  leach.  This  result  has  been  secured  without  a  particle  of 
expenditure  of  power  or  labor.  If  we  remove  slowly  the  liquor 
at  the  bottom,  we  gradually  let  the  weak  liquor  at  the  top  down 
on  the  strong  chips  below,  and  the  top  liquor  should  in  turn  be 
replaced  with  a  liquor  weaker  than  the  bark  to  be  treated.  In 
this  case  we  allow  the  solvent  to  pass  through  the  bark  and  not 
around  it,  it  becomes  saturated  with  soluble  matter,  and  no 
power  or  labor  is  expended  until  all  has  been  accomplished  that 
is  possible. 

Therefore,  this  general  rule  may  be  laid  down — for  the  head 
leach — no  liquor  should  be  removed  from  the  bottom  until  it 
reaches  the  practical  point  of  density  and  only  so  fast  as  it 
reaches  this  point.  This  may  seem  very  slow  work,  but  the 
point  to  be  gained  is  not  the  securing  of  a  large  amount  of  weak 
liquor  so  much  as  a  large  amount  of  tannin.  If  we  can  get 
that  tannin  in  the  shape  of  liquor  weighing  400  Twaddle,  it 
is  better  and  cheaper  than  to  get  four  times  the  quantity  of  10- 
degree  liquor. 

The  ideal  leach  should  never  be  idle  or  dormant,  nor  should 
it  be  allowed  to  flow  so  rapidly  as  to  be,  figuratively  speaking, 


LEACHING. 


51 


"beating  the  air,"  or  accomplishing  results  out  of  proportion  to 
the  power  and  labor  expended.  It  should  always  be  full  of 
liquor  in  motion,  until  exhausted  and  ready  to  be  pitched.  The 
liquor  in  a  leach  should  always  be  weaker  than  the  bark  to  be 
treated. 

In  a  series  of  twelve  leaches,  we  would  start  at  No.  I,  sup- 
posing all  to  be  filled  with  fresh  bark.  Fill  No.  I  with  weak 
liquor  or  water,  allow  to  soak  a  few  hours  and  pump  from  the 
bottom  of  1  to  the  top  of  2.  As  fast  as  the  liquor  reaches 
the  practical  point  of  saturation,  remove  to  the  storage  tank  for 
future  use  in  the  vats  or  pans,  and  pump  the  balance  to  the  suc- 
ceeding leach,  and  so  on. 

As  the  leaches  are  always  full  of  liquor  the  pump  lifts  only  a 
few  feet  and  uses  very  little  power.  This  is  practically  the  Hol- 
brook  system,  which  is  however  defective,  in  that  the  pump  in 
each  leach  is  operated  by  a  common  rod  and  all  run  at  the  same 
speed,  owing  to  the  fact  that  in  a  series  of  leaches  no  two  are  in 
the  same  condition.  The  speed  of  each  pump  should  be  regu- 
lated separately,  which  can  probably  be  best  done  with  an  air- 
lift pump  regulated  by  a  valve.  Jet  pumps  are  objectionable 
because  they  reduce  the  strength  of  the  liquor  by  condensation 
of  steam  and  they  will  not  handle  hot  liquors. 

In  this  way  we  have  always  a  stream  of  liquor  flowing  on  the 
top  of  each  leach  and  a  stream  of  stronger  liquor  from  the  bot- 
tom of  the  same  to  the  succeeding  stronger  leach.  From  the 
head  leach  we  have  from  the  bottom  a  constant  stream  of  sat- 
urated liquor  and  on  the  tail  leach  a  constant  stream  of  boiling, 
or  hot  water.  We  secure  a  maximum  of  tannin  with  a  minimum 
of  solvent,  economy  in  hot  water,  labor  and  power. 

The  most  seriously  defective  and  yet  one  of  the  most  com- 
mon systems  of  leaching  is  found  in  houses  having  only  one 
large  pump,  connected  by  water  logs  with  the  bottom  of  each 
leach.  A  wonderful  show  of  work  appears,  but  every  accepted 
principle  of  leaching  is  violated — the  liquors  are  all  lifted  the 
full  height  of  the  leach  and  from  six  to  ten  feet  higher,  they 
are  jerked  through  the  bark  so  rapidly  as  to  make  the  use 


52 


THE  MANUFACTURE  OF  LEATHER. 


of  enormous  quantities  necessary,  strong  liquor  is  forced  over 
weak  bark  and  gravity  lost  never  to  be  recovered,  fully  double 
the  boiler  capacity  is  required  and  the  final  or  finished  liquor  is 
not  over  one-third  the  strength  that  it  should  be.  To  pump  the 
liquor  from  the  bottom  of  any  leach  to  the  top  of  the  same 
leach  always  involves  a  loss  of  power,  labor  and  tannin — the 
bark  should  always  be  stronger  than  the  liquor.  It  is  more  de- 
sirable to  use  one  gallon  of  water  to  exhaust  a  given  quantity 
of  bark  than  to  use  ten,  as  well  as  very  much  cheaper. 

The  Vaughn  Machine  Company,  Peabody,  Mass.,  now  make 
leach  pumps  especially  designed  to  do  economical  work. 

The  latest  mode  of  quick  tanning  uses  borax  to  thoroughly 
cleanse  the  hide  or  skin  of  all  impurities,  thus  making  the  tex- 
ture very  open  and  receptive  to  the  tannin,  and  then  by  using 
borax  in  the  water  employed  for  leaching,  causes  a  very  gentle 
fermentation  of  the  bark,  either  oak  or  hemlock,  so  as  fully  to 
extract  the  tannin  and  allow  it  to  enter  into  combination  with 
the  hide  or  skin  without  becoming  in  any  degree  crystallized. 

For  grain,  split  buffed,  patent,  enameled,  furniture,  in  fact 
any  leather  which  requires  a  smooth  split,  there  is  no  agent  so 
good  as  borax,  which  can  be  used  in  the  soaks  and  in  the  water 
employed  for  leaching  the  bark.  The  borax  is  used  in  the 
proportion  of  five  pounds  to  the  one  thousand  gallons  of  water, 
or  a  little  more  borax  can  be  used  if  the  water  is  very  hard. 

The  borax  is  first  dissolved  in  boiling  water  and  then  added 
to  the  water  under  vigorous  stirring. 

There  is  no  patent  on  this  system  of  leaching  which  we 
have  advocated  in  this  chapter,  and  it  can  be  adopted  in  any 
leach  house  with  slight  expense.  The  question  of  regulating 
the  temperature  of  the  liquors  is  one  of  no  little  importance, 
and  is  dependent  on  the  material  to  be  treated.  The  tem- 
perature in  a  general  way  should  be  increased  as  the  liquors 
become  weaker.  After  the  proper  temperature  for  the  head 
leach  has  been  determined,  the  next  weaker  should  be  hotter 
and  the  temperature  increased  in  each  succeeding  weaker  leach 
until  the  boiling  point  is  reached  in  the  tail  leach.    As  a  rule 


LEACHING. 


53 


very  little  heat  is  needed  except  for  the  tail  leach,  the  liquor 
cooling  as  it  goes  forward  and  by  the  cooling  of  the  liquor 
resins  and  other  matter  insoluble  at  low  temperatures  are 
thrown  out  of  solution  and  are  removed  mechanically  in  pass- 
ing through  the  bark.  Under  certain  conditions,  as  in  winter 
weather,  when  the  liquors  cool  too  rapidly  it  is  convenient  to 
have  a  steam  coil  of  copper  pipe  in  the  bottom  of  each  leach 
below  the  false  bottom,  so  a  little  steam  can  be  used  if  necessary 
to  keep  the  liquor  up  to  the  proper  temperature. 

Extract  manufacturers  claim  to  secure  larger  yields  of  tannin 
from  their  bark  than  tanners,  and  doubtless  in  a  general  way 
they  do,  as  their  attention  can  be  concentrated  on  this  one 
point,  but  waste  never  profits  any  one  and  economical  results 
benefit  all. 

The  proper  leaching  of  bark,  although  apparently  a  difficult 
problem,  is  really  a  simple  one  when  once  understood.  Much 
of  the  difficulty  experienced  is  brought  about  by  the  lack  of 
proper  checks  and  records  when  a  new  experiment  is  tried. 

The  difficulty  does  not  end  here,  but  is  still  further  magnified 
by  erroneous  conclusions.  For  example,  an  experiment  is  tried 
and  proper  precautions  are  not  observed  in  getting  the  data; 
so  called  insignificant  matters  are  ignored,  although  the  success 
of  all  experiments  depends  upon  them,  and  at  the  end  of  the 
experiment  we  review  such  data  as  we  have,  and  immediately 
conclude  that  this  or  that  system  is  wrong  or  right,  when  in 
fact  by  taking  into  account  so  called  insignificant  matters  the 
conclusion  is  just  reversed. 

It  is  a  well  known  fact  that  a  soluble  body,  or  one  enveloped 
in  a  body  which  is  hardly  soluble,  will  dissolve  much  more 
quickly  in  a  fine  state  than  if  it  were  in  a  large  piece  or  pieces. 
For  instance,  granulated  sugar  will  dissolve  much  more  rapidly 
in  water  than  will  rock  candy,  although  both  are  identical  and  are 
only  presented  in  different  physical  states.  We  have  an  analo- 
gous case  in  bark,  large  pieces  of  ground  bark  corresponding  to 
the  rock  candy  and  finely  ground  bark  to  the  granulated  sugar. 
But  it  must  be  observed  that  water  will  dissolve  just  as  much  in 


54 


THE  MANUFACTURE  OF  LEATHER. 


either  case  if  given  sufficient  time  ;  that  is,  the  rate  of  solution 
is  slower  or  more  rapid,  as  the  case  may  be.  Water  will  pene- 
trate to  a  certain  depth  in  bark  in  a  given  time,  and  dissolve  a 
certain  amount  of  soluble  matter.  It  will  also  take  a  definite 
time  for  this  solution  in  the  bark  to  diffuse  into  the  surrounding 
water.  It  will  be  granted  that  the  finer  the  bark  the  more  rapidly 
will  this  diffusion  take  place.  Knowing  the  above  facts,  it  is 
evident  that  fine  bark  will  leach  more  perfectly  in  a  shorter 
space  of  time  than  coarse  bark.  It  is  well  known  to  tanners 
that  it  is  impossible  to  leach  the  bark,  or  to  get  any  liquor 
through  the  mass  of  bark  in  the  leach,  when  the  bark  is  ground 
too  finely,  and  when  the  old  system  of  draining  or  pumping  off 
is  used. 

This  difficulty  of  packing  may  be  overcome  by  always  keep- 
ing the  leach  full  of  liquor,  so  as  to  keep  the  bark  floating  and 
allow  the  liquor  to  pass  evenly  through  it.  It  is  possible,  how- 
ever, when  the  leach  has  packed  to  force  the  liquor  through  the 
mass  of  bark  with  pressure,  such  as  is  used  in  the  diffusion  sys- 
tem. It  even  then  happens  that  the  leach  or  cell  packs,  and  it 
is  then  necessary  to  reverse  the  pressure  to  partially  loosen  the 
mass  and  facilitate  the  circulation.  But  it  is  never  possible  to 
bring  about  the  proper  circulation  when  once  the  leach  or  cell 
has  packed.  But  why  should  an  unnecessary  amount  of  com- 
plication and  expense  be  added  when  it  is  possible  to  accom- 
plish the  same  results  in  a  much  more  simple  manner?  This 
can  be  done  in  the  following  way :  The  bark  is  comminuted  as 
finely  as  possible ;  that  is,  it  should  be  either  cut,  shaved  or 
shredded,  rather  than  ground  to  a  dust.  The  bark  so  prepared 
is  conveyed  to  the  leach,  which,  when  full,  is  properly  levelled 
off  and  covered  with  boards,  which,  in  turn,  are  held  down  with 
two  heavy  pieces  of  timber  slipped  under  cleats  fastened  to  the 
sides  of  the  leach  near  the  top.  The  bark,  therefore,  is  held 
down  when  the  leach  is  full  of  liquor.  The  leach  is  now  filled 
with  water  or  weak  liquor  and  when  full  it  can  be  pumped  off 
at  once,  but  it  is  preferable  to  allow  it  to  stand  over  night. 

The  pumping  is  done  from  the  bottom  of  the  leach  through 


LEACHING. 


55 


a  copper  or  brass  tube  which  extends  to  the  top.  This  pump- 
ing is  so  regulated  as  to  draw  off  just  as  much  liquor  as  is  run 
on  the  top,  so  as  always  to  keep  a  sheet  of  liquor  six  to  twelve 
inches  deep  on  the  top  of  the  bark.  This  sheet  of  liquor  plays 
an  important  part  and  really  determines  the  success  of  the  leach- 
ing, as  the  liquor  follows  directly,  without  channeling,  and  takes 
the  place  of  the  stronger  liquor  which  has  gone  before  it  when 
the  leaching  is  in  progress.  The  result  is  that  the  great  factor 
"  percolation  "  is  taken  advantage  of.  The  pumping  is  continued 
until  the  liquor  is  reduced  to  a  point  where  it  cannot  be  used 
in  the  tannery.  The  liquor  is  then  pumped  on  to  a  fresh  leach 
which  is  treated  in  the  same  manner  as  the  first,  which  has  just 
been  described,  and  so  on  through  the  whole  series  of  leaches. 
The  number  in  a  series  should  run  from  ten  to  twelve  or  more, 
depending  upon  the  depth  of  each  leach. 

It  is  well  known  that  the  longer  the  column  of  bark  through 
which  the  liquor  passes  the  stronger  is  the  liquor  and  more 
perfect  the  leaching.  But  there  is  a  limit  to  the  length  of  the 
column  in  any  one  leach,  as  when  we  exceed  a  certain  depth, 
say  ten  or  twelve  feet,  we  interfere  with  the  circulation,  or,  in 
other  words,  the  bark  packs  and  we  experience  the  difficulty 
alluded  to  above.  In  order  to  get  the  benefit  of  the  long  col- 
umn we  take  advantage  of  the  number  of  leaches,  as  we  can 
thereby  increase  the  length  of  the  column  to  any  extent 
desired. 

The  advantage  of  ten  or  more  leaches  is  apparent  when  the 
density  of  the  liquor  is  taken  as  it  comes  from  each  pump.  It 
will  be  found  that  the  difference  between  the  tail  leach  and  the 
one  next  to  the  head  will  be  from  one  to  one  and  a  half  degrees 
for  every  leach.  For  example,  suppose  there  are  twelve  leaches  ; 
the  water  leach  will  show  one  degree  and  the  eleventh  leach 
from  eleven  to  sixteen  degrees  barkometer,  and  so  on. 

By  observing  the  above  precaution  and  following  the  method 
described,  it  is  possible  to  make  a  stronger  liquor  of  the  same 
quantity  than  under  the  usual  conditions.  In  other  words,  we 
get  the  same  amount  of  tanning  substance  in  a  more  concen- 
trated form,  or  we  will  complete  our  leaching  with  less  water. 


56 


THE  MANUFACTURE  OF  LEATHER. 


Attention  should  be  called  to  the  fact  that  efficient  leaching 
cannot  be  done  with  cold  or  merely  warm  water  or  liquor.  It 
is  necessary  to  apply  the  water  or  liquor  on  the  tail  leaches  as 
hot  as  it  can  be  made,  say  from  205 °  to  212°  F.,  and  to  work 
the  leaches  actively. 

It  will  be  found  that  the  liquor  from  the  head  leach,  after  it 
has  been  pumped  down  in  density  until  it  is  ready  to  go  onto  a 
fresh  leach,  registers  from  1100  to  I20°F.  It  is  now  advisable 
to  pass  it  through  a  heater — especially  during  the  winter  months 
— before  putting  it  on  the  fresh  leach.  The  liquor  should  have 
such  an  initial  temperature  that  it  will  register  about  95 0  to 
ioo°  F.  after  having  passed  through  the  fresh  bark. 

It  will  be  found  that  by  working  according  to  these  temper- 
atures, about  950  gallons  of  a  22°  liquor,  barkometer  at  6o°  F., 
containing  about  2.75  per  cent,  tanning  substance,  can  be  ob- 
tained from  2,000  pounds  of  bark,  which  means  that  we  have 
extracted  about  90  per  cent,  of  the  tanning  substance  of  the 
bark.  On  the  other  hand,  if  the  temperature  of  the  liquor  is  10 
to  1  5  degrees  lower,  the  quantity  of  liquor  will  be  reduced  from 
20  to  25  per  cent. 

It  will  be  found  when  the  density  of  the  liquor  coming  off  the 
head  or  fresh  leach  is  noted  every  five  minutes — proper  correc- 
tion being  made  for  the  difference  of  temperature — that  the 
density  falls  regularly. 

If  the  figures  so  obtained  be  platted  on  paper — paper  ruled 
in  squares,  called  platting  paper,  such  as  engineers  use, — it  will 
be  found  that  the  fall  in  density  follows  a  curve  which  is  nearly 
a  parabola,  such  as  theory  indicates. 

The  most  convenient  and  accurate  check  on  the  efficiency  of 
the  leaching  is  the  measuring  and  weighing,  that  is,  taking  the 
density  of  the  liquor  from  each  leach. 

The  liquor  should  occasionally  be  analyzed,  to  show  whether 
the  ratio  of  tanning  substance  to  the  degree  of  barkometer  var- 
ies, and  to  what  degree.  Any  variation  should  be  allowed  for 
in  the  calculation  for  the  efficiency  of  leaching. 

It  might  be  said  that  just  as  efficient  leaching  can  be  done 


LEACHING. 


57 


when  the  bark  is  not  cut  or  ground  so  fine,  by  giving  longer 
time.  Tanners  will  submit  as  a  proof  the  analysis  of  the  "  spent 
bark"  according  to  which  there  is  more  tanning  substance  in 
the  coarse  than  in  the  fine  spent  bark,  which  has  been  leached 
in  a  much  shorter  space  of  time. 

//  is  not  known,  however,  that  the  difference  between  the  fresh 
and  spent  bark  (coarse)  is  in  the  liquors  in  an  available  form. 

It  will  be  found  when  the  liquors  from  the  coarse  bark  are 
measured — just  as  from  the  fine  bark — that  the  quantity  is  con- 
siderably less.  That  is,  the  amount  of  tanning  substance  really 
in  the  liquors  falls  short,  and  the  efficiency  of  leaching  is  not  so 
great. 

It  may  not  be  generally  known  that  bark  in  the  lyaways  loses 
comparatively  little  of  its  tanning  substance  in  two  or  three 
weeks  while  in  the  liquors.  It  cannot  be  said  that  the  reason 
of  this  is  that  the  liquor  is  as  strong  as  the  bark,  because  in 
putting  just  as  strong  or  even  a  stronger  liquor  on  a  fresh  leach 
we  get  a  proportionally  stronger  liquor.  So  there  is  something 
else  beside  simply  soaking.  When  a  warm  or  hot  liquor  is  put 
on  a  leach  and  left  to  stand,  the  temperature  of  the  top  liquor 
falls  very  rapidly. 

When  this  cold  liquor  passes  down  through  the  bark  it  re- 
duces the  temperature,  so  that  it  is  alternately  heated  and  cooled, 
which  is  fatal  to  perfect  leaching,  as  the  temperature  of  bark 
and  liquors  should  be  steadily  increased  toward  the  tail  or  wa- 
ter leach.  The  only  way  to  do  this  properly  is  to  work  the 
leaches  actively.    Leaches  ought  to  run  day  and  night. 

Some  tanners  still  advocate  putting  the  spent  liquor  from 
"rockers"  on  the  tail  leach.  The  very  small  amount  of  tan- 
ning substance  saved  (such  liquors  do  not  contain  at  the  utmost 
over  one-half  of  one  per  cent,  and  usually  from  two-tenths 
to  three-tenths  per  cent,  of  tanning  substance)  is  completely 
overbalanced  by  the  large  amount  of  filth,  non  -tanning  sub- 
stance, etc.,  always  present  in  such  liquors. 

What  is  the  object  of  applying  a  mellow  liquor,  weak  in  tan- 
ning substance,  to  a  green  hide  from  the  beam  house?    It  is  to 


58 


THE  MANUFACTURE  OF  LEATHER. 


purge  it  of  the  lime  and  filth.  If  we  are  so  anxious  to  get  rid 
of  these  on  the  one  hand,  why  should  we  take  particular  care 
to  recover  them,  as  it  were,  on  the  other? 

The  lime  which  is  kept  in  solution  by  means  of  the  organic 
acids  present  in  the  liquor,  is  partially  precipitated  in  the  bark 
as  soon  as  the  acid  is  absorbed  by  it.  The  consequence  is  that 
there  is  considerable  tanning  substance  fixed  which  cannot  be 
extracted  later  on. 

At  any  rate,  it  is  now  apparent  that  it  is  better  and  more 
economical  to  run  this  liquor  away,  and  instead  put  nothing  but 
clear  water  on  the  leach.  We  shall  then  not  only  get  the  same 
amount  of  tanning  substance,  but  in  a  more  desirable  form,  as 
non-tanning  substances,  such  as  exist  in  spent  liquors,  are  car- 
ried forward  unchanged  in  the  leaches. 

The  last  system  of  leaching  bark  which  has  been  described  in 
this  chapter  is  in  use  by  the  American  Oak  Leather  Co.,  Cin- 
cinnati, Ohio,  and  the  plant  was  built  by  Byron  Holbrook, 
Milwaukee,  Wis.  The  leach  house  of  the  American  Oak 
Leather  Co.,  is  the  most  modern  in  the  world,  about  $25,000 
having  been  spent  on  it. 

Stephen  Dow  &  Co.,  and  E.  C.  Cottle  &  Son,  Woburn,  Mass., 
and  Beggs  &  Cobb,  Winchester,  Mass.,  have  recently  put  in  new 
systems  of  leaching  hemlock  bark.  The  leaches  are  circular 
in  form,  12  feet  in  diameter  and  14  feet  deep.  There  is  a  bark 
conveyer  overhead  and  a  conveyer  underneath  for  the  spent 
tan,  leaving  the  leach  house  clear  of  obstructions. 

The  water  that  goes  on  the  head  leach  is  about  1400  F.  in 
temperature,  but  the  water  that  is  put  on  the  tail  leaches  is  at 
212°  F. 

Tanners  who  use  bark  are  paying  greater  attention  than  ever 
to  their  leaching  systems.  The  depression  in  business  and  lack 
of  profits  is  forcing  manufacturers  to  economize  in  every  direc- 
tion, and  save  all  that  is  possible  in  their  processes.  Many 
tanners  are  now  convinced  that  it  is  better  to  replace  old  leaches 
and  faulty  methods  by  modern  improvements,  rather  than  de- 
ceive themselves  with  apparently  saving  expenses  by  sticking 
to  superseded  and  wasteful  methods. 


LEACHING. 


59 


Tanners  with  old-fashioned  square  leaches,  set  in  the  ground, 
which  have  to  be  laboriously  thrown  out  when  spent,  are  now 
building  the  popular  round  leaches,  placed  above  ground,  and 
supplied  with  openings  at  the  bottom,  through  which  with  little 
effort  a  man  can  quickly  feed  the  spent  tan  to  the  conveyer 
under  it. 

There  seems  to  be  much  more  inclination  among  tanners  to 
pump  their  leaches  more  frequently.  Careful  foremen  state 
that  the  best  way  is  to  keep  the  ground  bark  covered  with  liquor, 
and  in  this  manner  prevent  channels  being  formed  in  the  leach. 
Bark  ground  finely  is  particularly  apt  to  pack,  unless  pumped 
over  carefully  and  properly.  It  is  said  that  if  a  leach  is  simply 
pumped  off  and  then  refilled,  channels  are  more  liable  than  when 
there  is  a  good  head  of  liquor  on  the  top  of  the  leach,  which 
percolates  evenly,  and  is  as  evenly  replenished  at  the  top. 

Some  tanners  prefer  flooding.  Of  course,  to  enable  the  pumps 
to  be  kept  working  constantly,  a  certain  amount  of  liquor  has 
to  be  thrown  into  storage  tanks.  Those  who  are  leaving  the 
least  percentage  of  tannin  in  their  bark  say  they  put  moderate 
heat  on  the  new  or  head-leach,  but  that  the  other  leaches  get 
red-hot  liquor  all  the  time.  A  successful  oak  sole  leather  tan- 
ner claims  to  get  1,000  gallons  of  22  degree  liquor  from  2,000 
pounds  of  oak  bark.  When  asked  how  many  pounds  of  oak 
leather  he  made  from  a  cord  of  bark,  he  retired  into  eloquent 
silence,  feeling  that  his  chief  success  in  meeting  competition  lay 
in  his  ability  to  manufacture  in  the  most  improved  manner  at 
the  lowest  cost,  and  to  keep  his  own  counsel.  Numbers  of  tan- 
ners are  leaching  to-day  exactly  the  same  as  20  years  ago. 
They  simply  pump  one  leach  into  another  in  rotation  and  not 
simultaneously,  and  let  it  go  at  that.  It  is  now  generally  ac- 
cepted, however,  that  more  can  be  obtained  from  bark  by  hav- 
ing pumps  in  each  leach,  and  keeping  all  of  them  actively  at 
work  all  day  and  all  night. 

The  grinding  of  bark  is  being  done  much  more  carefully  than 
formerly.  Some  tanners  screen  their  bark  after  grinding,  and 
throw  all  coarse  pieces  into  the  mill  again.    Unless  bark  is  thor- 


6o 


THE  MANUFACTURE  OF  LEATHER. 


oughly  and  properly  ground  it  will  not  leach  as  it  ought  to.  It 
is  expensive  and  wasteful  to  operate  poor  mills  and  poor  leach- 
ing systems.  Better  for  tanners  to  keep  up  to  date,  to  incur  the 
expense  attendant  on  improvements,  and  thus  be  in  line  for 
making  leather  under  the  best  conditions,  and  at  the  lowest 
cost. 

The  most  enterprising  tanners  keep  a  ledger  account  for  each 
leach.  They  weigh  the  bark  before  grinding,  and  measure  the 
liquor  produced.  All  this  means  careful  watching  and  figuring. 
But  it  also  means  stoppage  of  leaks,  and  as  well  as  an  intimate 
knowledge  of  results  that  are  actually  obtained.  The  path  from 
a  fool's  paradise  to  the  bankruptcy  courts  is  being  trodden  every 
day  by  weary  feet.  Chemical  analysis  has  rudely  awakened  more 
than  one  tanner  to  the  true  condition  of  his  affairs  in  his  leach- 
house  and  elsewhere.  If  a  tanner  is  satisfied  that  he  is  properly 
exhausting  his  bark,  he  should  be  all  the  more  willing  to  get  a 
chemist's  endorsement  of  his  success.  Possibly,  however,  he 
may  find  that  after  all  he  was  leaving  a  percentage  of  tannin 
which  might  have  been  saved.  There  is  undoubtedly  a  wave 
of  reform  in  leaching  systems,  but  it  is  equally  true  that  many 
tanners  are  still  laboring  in  old  wasteful  ruts.  Only  recently 
an  oak  leather  tanner  confessed  that  the  oak  bark  that  he 
dusted  into  his  layaways  contained  much  more  tannin  after 
being  cast  out  than  he  imagined.  He  awoke  to  the  fact  that 
by  dumping  this  bark  into  a  tank  and  using  hot  liquors,  he  was 
able  to  exhaust  it  much  better  than  by  simply  using  cold  runs. 

What  with  liquor  heaters  and  coolers  of  excellent  design  on 
the  market,  cheap  pumps  and  good  bark  mills,  there  seems  to 
be  no  reason  why  those  tanners  who  claim  to  be  leaving  only  I 
per  cent,  or  less  of  tannin  in  their  bark  should  be  as  few  as  they 
are  at  present. 

One  of  the  best  methods  for  leaching  tanning  material  is  that 
known  as  the  Press-leach  system.  For  oak  bark  it  is  specially 
suited.  Any  number  of  leaches  up  to  12  may  be  taken  to  con- 
stitute a  set.  For  example,  let  us  take  a  set  of  six,  which  may 
be  arranged  in  a  row  of  six,  or  in  two  rows  of  three  side  by 


LEACHING. 


61 


side,  and  fill  each  with  bark.  Each  pit  leach  is  fitted  with  a 
false  bottom  raised  about  6  inches  from  the  bottom  of  the  pit, 
through  which  liquor  but  not  bark  may  easily  pass.  A  pipe  or 
trunk  connects  the  bottom  of  No.  I  pit  to  the  top  of  No.  2,  and 
the  whole  series  is  in  the  same  manner  connected,  so  that 
the  liquor  passes  through  each  pit  of  the  series  on  to  the  top 
of  the  next  stronger.  The  liquor  from  No.  6,  the  strongest, 
may  be  used  for  the  pits.  Water  or  weak  liquor  is  run  on  to 
No.  I  and  slowly  percolates  through  the  bark,  passing  on  to 
the  top  of  No.  2,  and  so  on  up  to  No.  6,  gaining  in  strength  as 
it  advances.  By  this  means  the  most  perfect  leaching  is  ac- 
complished, though  in  practice  it  is  found  difficult  thoroughly 
to  spend  bark.  Before  No.  I  is  cast,  it  is  necessary  to  run 
on  one  or  more  hot  waters.  This  dissolves  a  large  amount  of 
"  reds "  and  resinous  matters,  together  with  the  rest  of  the 
tannin,  but  as  the  liquor  passes  through  the  succeeding  pits, 
which  cool  down,  the  reds  and  resinous  matters  separate  out, 
and  are  filtered  off.  A  copper  coil  under  the  false  bottom  of 
each  pit  through  which  steam  may  be  passed  is  also  beneficial. 

When  the  material  in  No.  I  is  spent,  it  is  cast  and  filled  with 
fresh  bark,  and  becomes  the  best  leach,  and  is  connected  to  No. 
6,  No.  2  becoming  the  spender,  and  in  this  manner  each  pit  in 
its  turn  becomes  the  hinder  pit.  By  this  system  a  constant 
stream  of  water  or  weak  liquor  is  run  on  the  top  of  the  weakest 
pit,  and  a  stream  of  the  strong  liquor  may  be  taken  from  the 
bottom  of  the  strongest.  It  saves  much  labor,  pumping,  etc., 
and  gives  better  results  than  some  other  systems.  A  little  care 
must  be  taken  in  packing  the  bark — packing  loosely,  so  that 
the  liquor  may  flow  easily  and  avoid  clogging  or  channels. 

The  system  which  we  have  described  in  the  earlier  part  of 
the  chapter  is  considered  by  the  American  tanners  to  be  an 
improvement  on  the  above,  and  certainly  presents  great  ad- 
vantages. The  liquor,  instead  of  being  allowed,  by  finding  its 
level,  to  flow  from  one  pit  to  the  other,  is  pumped  over  by  an 
air  lift  pump  attached  to  each  pit,  thus  keeping  the  levels  in 
each  pit  the  same.    It  is  important  never  to  let  a  leach  run  dry, 


62 


THE  MANUFACTURE  OF  LEATHER. 


as  the  material  by  so  doing  sinks  down  and  becomes  sodden, 
and  is  liable  to  heat,  and  prevents  proper  percolation. 

THE  BARKOMETER. 

In  the  use  of  the  hydrometer,  or  barkometer  as  it  is  com- 
monly termed  by  tanners,  it  must  be  kept  in  mind  that  it  is  de- 
signed simply  to  determine  the  density  of  any  fluid  more  dense 
than  water,  as  compared  with  pure  water.  It  does  not  indicate 
of  what  the  fluid  consists  ;  the  density,  or  specific  gravity,  of 
other  heavy  fluids  can  be  shown  just  as  readily  as  that  of  a 
solution  of  tannin,  and  be  indicated  on  the  stem  in  the  same 
way.  The  purity,  or  comparative  purity,  of  a  tanning  liquor 
being  known,  the  barkometer  will  show  its  comparative  value. 

The  barkometer  is  graded  so  that  when  it  is  placed  in  water 
at  6o°  temperature  it  will  stand  at  0°,  and  the  tanning  liquors 
to  be  weighed  by  it  should  be  at  the  same  temperature;  but  as 
fluids  contract  and  expand  largely  as  they  are  cooled  or  heated, 
if  the  liquor  is  warmer  than  6o°,  the  barkometer  will  indicate 
less  density  than  it  should  ;  if  colder,  greater  density.  This 
shows  the  value  of  a  thermometer,  to  be  used  in  connection 
with  a  barkometer,  as  the  sense  of  touch  cannot  be  relied  upon 
to  indicate  the  degree  of  heat.  Barkometers  made  of  glass  are 
more  reliable  than  any  others,  for  they  expand  and  contract 
less,  and  although  in  preparing  the  liquors  it  is  not  uncommon 
also  to  judge  of  their  strength  by  the  taste,  still  this  is  not  a 
good  guide,  and  no  tanner  can  afford  to  be  without  a  barko- 
meter. 

It  is  perhaps  necessary  also  to  remark  that  this  instrument 
is  applicable  only  to  freshly-made  liquors;  for  otherwise  con- 
fusion and  want  of  confidence  might  ensue  upon  finding  that  it 
sinks,  sometimes,  to  a  corresponding  degree  in  spent  liquor, 
and  which  is  owing  to  the  fact  that  the  alterations  which 
tanning  liquors  undergo  during  use  and  exposure  may  not 
diminish  their  density,  though  they  impair  and  destroy  their 
tanning  power. 


LEACHING. 


63 


BARK  MILLS. 

Oak  and  hemlock  bark  are  the  standard  tanning  materials  of 
the  United  States.  In  Europe  and  other  foreign  countries  the 
following  materials  are  principally  used — valonia,  myrabolans, 
gambier,  sumac,  divi-divi,  mimosa  bark,  quebracho,  bark  of  the 
oak,  fir  and  less  important  trees,  and  bark  extracts.  The 
manipulation  of  bark  so  that  its  tannin  can  be  extracted  is  a 
problem  that  has  attracted  the  attention  of  many  ingenious 
minds.  Numbers  of  patents  have  been  secured  for  machines 
and  appliances  for  peeling,  rossing,  cutting,  grinding,  crushing 
and  rolling  bark. 

In  days  gone  by,  when  bark  was  plentiful,  it  was  lavishly  and 
wastefully  used.  It  is  not  more  than  ten  years  ago  since  even 
the  best  tanners  in  this  country  were  getting  much  less  tannin 
from  their  bark  than  they  are  to-day. 

Bark  is  liable  to  be  placed  before  the  tanner  in  three  differ- 
ent conditions — dry,  damp  or  green.  These  differences  have 
called  forth  special  methods  for  handling  bark  in  any  stage  to 
the  best  advantage.  Many  theories  have  been  advanced  in 
regard  to  the  best  methods  of  preparing  bark  so  that  its  tannin 
can  be  most  thoroughly  extracted. 

A  study  of  the  Patent  Office  reports,  relating  to  the  machines 
and  appliances  for  reducing  bark,  is  very  interesting.  It  is  to 
be  regretted  that  the  very  old  records  are  so  bare  of  details. 
They  simply  mention  the  date  of  the  patent  and  the  name  of  the 
patentee.  Modern  reports  from  the  Patent  Office  give  as  full 
information  in  regard  to  patents  as  could  be  desired.  A  some- 
what melancholy  history  is  attached  to  the  various  bark  mill 
patents.  One  can  easily  imagine  the  "big  thing"  that  the  in- 
ventors thought  they  possessed  in  patents  which  have  been 
forgotten  long  ago.  We  suppose  many  of  the  inventions  did 
good  service  in  their  day,  and  did  not  sink  into  obscurity  with- 
out yielding  some  compensation  to  those  who  thought  them 
out. 

The  earliest  patent  for  a  bark  mill  is  dated  October  25,  1826, 
and  was  awarded  to  C.  Foss.    This  machine  consisted  of  six- 


64 


THE  MANUFACTURE  OF  LEATHER. 


teen  knives  on  a  swiftly  revolving  wheel.  It  certainly  cut  the 
bark,  but  in  a  crude  and  wasteful  manner.  It  is  instructive  to 
recall  this  patent,  remembering  that  we  have  bark  cutters  to-day 
that  work  on  the  same  principle,  although  vastly  improved  in 
every  respect.  In  1828,  A.  Bull  received  a  patent  for  a  bark 
mill.    This  was  on  the  segment  plan  which  is  so  familiar  to-day. 

Then  followed  a  number  of  inventions  for  breaking  the  bark 
in  different  ways  in  a  hopper,  from  which  it  fell  between  metal 
teeth  or  segments  arranged  in  different  ingenious  ways  to  pul- 
verize the  bark,  and  render  it  easy  for  leaching. 

The  main  object  of  tanners  is  to  break  up  the  bark  so  that 
the  tannin-cells  can  be  easily  dissolved  by  water  or  weak 
liquors.  At  present  there  are  two  leading  methods  of  grinding 
or  reducing  bark.  Many  tanners  advocate  what  is  called  the 
Beecher  system  of  grinding  between  segments.  Other  tanners 
favor  cutting  or  shaving,  to  reduce  the  bark  into  shreds  which 
can  be  readily  leached.  A  few  years  ago  attention  was  called 
to  bark-rolling  machines.  The  idea  was  to  take  freshly  ground 
bark,  and  to  place  it  under  heavy  metal  rollers,  so  that  the  bark 
cells  could  be  flattened  out  and  in  a  way  that  would  yield  their 
tannin  easily  when  soaked.  It  took  so  much  power  to  drive 
these  rollers  that  their  use  has  been  confined  to  comparatively 
few  places. 

There  have  been  fads  in  the  bark  business  just  as  in  every 
other  line.  Many  years  ago  it  was  considered  wise  to  remove 
the  ross  or  outside  covering  from  the  bark  before  it  was  ground 
in  the  mill.  Elaborate  theories  were  advanced  proving  that 
the  flesh  or  part  of  the  bark  next  to  the  tree  containing  the 
tannin  would  be  more  profitable  to  use  by  itself  in  the  leaches. 
It  was  found,  however,  that  the  time  and  trouble  necessary  to 
take  off  the  ross  was  not  repaid  by  results.  Tanners  acknowl- 
edge to-day  that  while  the  ross  of  the  bark  is  not  a  tanning 
agent,  it  contains  certain  properties  when  ground  in  with  the 
flesh  of  the  bark  that  help  to  make  good  leather.  Besides,  the 
value  of  ross  as  fuel  is  no  small  item  in  a  large  tannery.  We 
can  well  recall  the  time,  some  twelve  years  ago,  when  O.  K. 


LEACHING. 


65 


Lapham,  who  then  lived  in  Chicago,  introduced  Dr.  H.  E. 
Starcke  to  the  tanners  of  the  United  States.  Mr.  Lapham  was 
a  student  of  the  properties  of  bark,  and  in  common  with  James 
E.  Mooney  and  the  late  Jackson  S.  Schultz,  he  employed 
this  young  German  chemist  to  analyze  some  alleged  "  spent 
tan  "  from  leading  tanneries.  The  analyses  startled  and  aroused 
the  tanners,  who  were  disposed  at  first  to  doubt  their  accuracy. 
The  chemist's  science,  however,  stood  the  tests  brought  against 


Fig.  4. 


FRONT  VIEW. — BARK    CUTTER. —  (JONES'  PATENTS.) 


it,  and  an  era  of  reform  was  inaugurated  in  the  manipulation  of 
bark  which  is  still  active  to-day.  With  improved  bark  mills, 
and  a  better  understanding  of  the  methods  of  leaching,  much 
less  tannin  is  wasted  than  formerly.  There  is  still,  however, 
room  for  improvement  in  the  latter  direction.  It  would  seem 
almost  impossible  to  surpass  the  machines  now  on  the  market 
for  grinding  or  cutting  bark. 
5 


66 


THE  MANUFACTURE  OF  LEATHER. 


Bark  mills  are  manufactured  by  Ott's  Bark  Shaving  Mill  Co., 
La  Crosse,  Wis. ;  Byron  Holbrook,  Milwaukee,  Wis. ;  Eureka 
Bark  Mill  Co.,  Lancaster,  Pa. ;  W.  F.  Mosser  &  Son,  Allentown, 
Pa.,  and  Shapley  and  Wells,  Binghamton,  N.  Y.  J.  T.  Phillips, 
Grand  Rapids,  Mich.,  makes  a  disintegrator  which  is  valuable 
to  bark  users,  and  is  claimed  to  furnish  results  not  to  be  had 
by  the  use  of  any  other  machine  on  the  market. 

We  show  in  Figs.  4  and  5  a  front  and  rear  view  of  a  bark 


Fig.  5. 


REAR  VIEW. — BARK  CUTTER. —  (JONES'  PATENTS.) 


cutter  made  by  the  Vaughn  Machine  Company,  Peabody,  Mass., 
and  which  is  largely  used  by  tanners  in  all  parts  of  this  coun- 
try and  in  many  parts  of  Europe. 

A  prominent  tanner  writes  the  builders  as  follows:  "That 
after  a  thorough  test  of  four  months  with  the  cutter  they  are 
satisfied  that  it  better  prepares  the  bark  for  leaching,  and  gives 
better  results  in  every  way,  than  any  other  machine  they  have 
known  in  35  years'  experience  as  tanners." 


LEACHING. 


67 


In  construction  it  is  simplicity  itself,  with  no  gears,  chains 
and  apparatus  to  get  out  of  order.  There  are  two  discs,  the 
front  or  breaking  disc  revolving,  and  the  rear  or  fine  cutting 
disc  stationary.  The  bark  is  thrown  into  the  hopper  in  front 
by  armfuls,  when  the  revolving  disc,  in  which  arc  set  six 
knives,  cuts  or  breaks  it  up  into  small  pieces,  which  then  pass 
through  compartments  in  the  revolving  disc  onto  the  face  of 
the  rear  disc,  around  which  it  is  carried  until  cut  up  fine  by 
the  twenty  knives  which  are  set  in  this  disc,  and  passed 
through  the  small  throats  or  apertures  in  which  these  knives 
are  set,  and  falls  down  into  the  conveyer  at  the  rear  of  the 
same.  All  practical  tanners  will  see  that  the  bark  being  cut 
up  into  small  pieces  by  the  first  disc,  before  reaching  the  knives 
where  it  is  cut  fine,  it  is  impossible  to  get  large  shavings,  which 
cannot  be  avoided  in  any  other  way. 

One  excellent  feature  also  is  that  the  rear  or  stationary  disc 
is  made  sectional,  there  being  five  sections  with  four  knives 
in  each  one,  so  there  is  absolutely  no  trouble  nor  time  lost  in 
sharpening,  as  each  mill  is  fitted  with  two  complete  sets  of 
sections  and  knives ;  thus,  when  the  knives  become  dull,  the 
sections  can  in  a  few  minutes'  time  be  taken  out  and  replaced 
with  the  sections  containing  sharp  ones,  which  virtually  gives 
the  purchaser  the  wear  of  two  mills,  as  the  sections  are  the 
principal  parts  that  will  wear  out.  This  cutter  is  strictly  port- 
able and  costs  very  little  to  set  up ;  no  more  in  fact  than  for 
an  ordinary  machine,  as  it  has  simply  to  be  bolted  down  to  the 
floor  over  the  conveyer  or  elevator  shute,  and  belted  onto  from 
a  countershaft  above. 

Solidity  is  another  feature  the  builders  claim,  and  any  tanner 
will  appreciate  that  point  and  to  get  a  bark  cutter  that  will  not 
break  nor  get  out  of  order  easily. 

The  weight  complete  is  4000  lbs.:  speed  from  250  to  300 
revolutions  per  minute.  Pulley  used  36  inches  diameter,  12 
inches  face.    Dimensions:  6  ft.  long,  4  ft.  wide,  4  ft.  high. 

Capacity:  The  builders  claim  for  it  30  cords  per  day,  wet  or 
dry,  and  guarantee  that  the  quality  as  well  as  the  quantity  done 
will  suit  the  most  exacting. 


68 


THE  MANUFACTURE  OF  LEATHER. 


In  Fig.  6  is  shown  the  new  automatic  knife  grinder  for  the 
Jones  patent  bark  cutter  and  other  cutters.  It  weighs  only 
700  pounds,  and  is  simple,  durable  and  effective. 

Emery  wheel  made  special  and  can  be  run  dry  or  in  water 
as  preferred.  Warranted  not  to  heat  or  draw  temper  of  the 
knife.    Sizes:  32  inch,  36  inch,  50  inch.    Emery  wheel,  22 


Fig.  6. 


AUTOMATIC  KNIFE  GRINDER. 


inch  diameter,  \y2  inch  face.  Driving  pulleys,  10  inch  diam- 
eter, 3  inch  face,  tight  and  loose,  and  warranted  to  run  140 
revolutions  per  minute.  This  machine  is  built  by  the  Vaughn 
Machine  Company,  Peabody,  Mass. 

BARK-CONVEYER. 

This  invention,  which  was  patented  May  1,  1883,  by  Mr. 
Oliver  A.  Zane,  of  Peabody,  Massachusetts,  relates  to  the  end- 
less chains  and  lags  or  devices  connected  therewith  for  convey- 
ing bark  or  various  other  matters  from  one  position  to  another, 
it  being  specially  useful  for  what  in  tanneries  are  termed 


LEACHING. 


69 


"ground-bark  conveyers,"  each  of  which  in  the  main  consists  of 
an  endless  chain  and  a  series  of  lags  or  bars,  such  lags  or  bars 
being  arranged  at  equal  distances  apart  and  fixed  or  held  to  the 
chain,  and  the  latter  being  extended  around  and  supported  by 
two  spider  or  sprocket  wheels.  The  conveyer  so  constructed  is 
arranged  to  extend  within  a  trough,  through  which,  lengthwise 
of  it,  the  chain  in  moving  drags  the  lags  and  causes  them  to 

Fig.  7. 


force  along  with  them  the  bark  or  material  to  be  transferred 
from  one  position  to  another  or  higher  one. 

Fig.  7  is  a  top  view,  Fig.  8  a  longitudinal  section,  Fig.  9  a 
side  view,  and  Fig.  10  a  transverse  section,  of  part  of  a  conveyer 
containing  Zane's  improvement.  Fig.  1 1  is  an  edge  view  of 
one  of  the  links  of  the  endless  chain  of  such  conveyer.    Fig.  12 


7o 


THE  MANUFACTURE  OF  LEATHER. 


is  a  rear  elevation,  and  Fig.  13  a  front  elevation,  of  one  of  the 
lags  of  the  conveyer. 

Previous  to  this  invention  it  had  been  customary  to  construct 
certain  links  of  the  chain  with  ears  extending  from  them  and 
formed  as  shown  in  Figs.  14  and  15  at  a  a,  the  lag  being  fast- 
ened to  the  link  by  screws  passing  through  the  ears.  These 
ears  are  very  liable  to  become  broken  from  the  link,  and 
thereby  render  it  useless,  and  to  necessitate  the  substitution  of 
another,  frequently  at  considerable  expense,  inconvenience,  or 
loss  to  the  tanner.  With  this  invention  the  links  of  the  chain 
are  all  alike  and  require  no  such  means  of  connection  of  any  of 


Fig.  12. 


them  with  a  lag,  which  may  be  attached  to  any  one  of  them 
throughout  the  chain.  In  Figs.  7,  8,  9,  and  10,  these  links  are 
shown  at  A  A  A  and  a  lag  at  B.  Each  link  tapers  lengthwise 
and  crosswise ;  or,  in  other  words,  it  is  not  only  dovetailed  in 
form  lengthwise  of  it,  but  is  also  dovetailed  transversely  of  it,  as 
represented.  It  is  hooked,  as  shown  at  c,  at  one  end  to  clasp 
the  cylindrical  end  part,  d,  of  the  next  link,  each  link  being 
notched  as  shown  at  e  and  g,  to  enable  it  to  be  coupled  with 
or  uncoupled  from  another  link.  The  lag  B  has  made  in  it  a 
notch  or  recess,/",  to  receive  a  link,  such  notch  or  recess  being 
tapering  or  dovetailed  both  lengthwise  and  transversely  of  it  to 
receive  and  fit  to  a  link,  which,  previous  to  being  engaged  with 


LEACHING. 


71 


its  two  next  adjacent  links,  between  which  it  is  to  extend,  is  to 
be  placed  within  the  notch  or  recess.  Instead  of  this  double 
dovetailed  notch  or  recess  being  formed  immediately  within  the 
bar  or  lag,  it  may  be  in  a  block  or  piece  of  metal  screwed  or 
fastened  to  the  lag.  While  the  dovetails  of  the  link  will  keep 
the  lag  from  slipping  off  the  link  in  one  direction  transversely 
and  in  another  lengthwise  of  it,  the  next  link,  by  extending 
transversely  beyond  the  lag-link,  as  shown,  will  prevent  the  lag 
from  slipping  off  its  link  in  the  opposite  direction  longitudinally 
of  the  link.  Thus  by  having  to  the  lag  a  double  dovetailed 
recess  or  link-socket,  as  described,  and  by  having  the  chain- 
links  made  as  represented,  it  is  possible  not  only  to  readily 
adapt  a  lag  to  any  link  of  the  chain,  but  also  to  keep  it  in  place 
without  any  screws,  ears,  or  other  fastenings,  as  heretofore 
employed  ;  and  when  a  tanner  is  provided  with  auxiliary  links 
he  can,  in  case  of  breakage  of  any  one  of  the  chains,  readily 
supply  its  place  with  another. 

Instead  of  a  lag,  a  bucket  may  be  used,  and  be  provided 
with  a  double  dovetailed  recess  or  link-socket,  as  described,  to 
receive  a  link  of  the  chain. 

THE  TAN  PRESS. 

The  machine  shown  in  Fig.  16  is  made  by  William  F.  Martin, 
Salem,  Mass.,  and  is  indispensable  in  every  well  equipped 
tannery,  for  the  preparation  of  the  spent  tan  for  fuel.  The 
machine  is  compact,  simple  in  construction,  and  easily  kept  in 
order.  Ten  cords  of  wet  dripping  tan  can  be  run  through  the 
press  in  a  day,  pressed  dry,  and  it  is  ready  to  burn  under  the 
boiler  without  the  addition  of  coal  or  any  other  fuel.  At  this 
late  day  it  is  perhaps  unnecessary  to  speak  of  the  economy  of 
a  tan  press  over  drying  the  tan  in  the  sun,  or  over  the  boiler, 
or  having  it  carted  away  as  waste.  Suffice  it  to  say,  that  no 
tanner  who  has  used  a  press  would  think  of  doing  business 
without  one. 

Yet  as  some  tanners  are  still  doing  business  without  a  press, 
it  may  be  said  to  them  that  the  economy  of  one  is  this  :  That 


72 


THE  MANUFACTURE  OF  LEATHER. 


by  the  means  of  an  elevator,  consisting  of  buckets  on  an  end- 
less chain,  the  spent  tan  is  taken  from  some  convenient  deposi- 
tory near  the  vats  or  leaches,  to  a  bin  above  the  tan  press.  It 
feeds  itself  through,  and  is  from  there  deposited  in  front  of  the 
boiler,  where  it  is  ready  to  burn,  thereby  saving  all  labor  except 
the  little  of  getting  the  tan  to  the  place  where  it  is  first  taken 


Fig.  i 6. 


SALEM  ROTARY  TAN  PRESS. 


up  by  the  elevator.  Thus  is  there  a  good  fuel  convenient  for 
use  at  almost  no  cost. 

Diagram  of  press  is  shown  in  Fig.  17.  After  the  tan  has 
been  thrown  into  the  hopper  D  it  is  then  forced  by  the  fluted 
feed  roll  B  through  the  pressure  rolls  A  A,  and  sliding  down 
delivery  plate  E,  it  falls  in  front  of  the  boiler  ready  to  be 


LEACHING. 


73 


shoveled  into  the  furnace.  The  water  is  taken  care  of  by  the 
revolving  brass  strainer  roll  C. 

The  press  is  run  by  a  4  in.  belt,  requires  but  little  power  and 
should  be  run  at  a  speed  of  75  revolutions. 


Fig.  17. 


i>ia<;ram  ok  tan  press. 


CHAPTER  V. 


TANNING  EXTRACTS. 

The  use  of  extracts  in  tanning  has  grown  to  large  propor- 
tions during  the  past  fifteen  years.  There  are  many  advantages 
in  the  use  of  such  extracts.  The  liquors  are  always  under  per- 
fect control,  that  is,  by  putting  in  so  much  extract  the  quan- 
tity of  tanning  material  is  known.  It  does  away  with  the 
storing  of  large  quantities  of  bark,  as  one  barrel  of  extract  is 
equivalent  to  about  one  cord  of  bark — 128  cubic  feet.  Where 
space  costs  money  this  is  quite  an  item,  and  it  also  saves  inter- 
est and  insurance  on  the  bark. 

There  is  no  difference  in  the  fibre  produced  by  bark  liquors 
and  pure  tanning  extracts,  as  properly  prepared  extract  is 
nothing  more  than  concentrated  liquor.  Tanning  extracts  in 
common  use  in  the  United  States  are  made  from  chestnut  oak 
bark,  chestnut  oak  wood,  chestnut  wood,  hemlock  bark,  quer- 
citron bark,  canaigre  and  sumac ;  black  oak  bark  extract  is 
used  to  give  a  bloom  to  leather,  and  coloring  or  dyeing  extracts 
are  made  from  logwood,  fustic  and  from  a  large  number  of 
other  materials. 

The  chestnut  tree,  after  it  is  felled,  is  peeled  of  the  bark, 
which  is  objectionable  on  account  of  the  coloring  matter  which 
it  contains.  The  chestnut  oak  tree  is  used  as  it  comes  from  the 
stump.  The  chestnut  tree  and  the  chestnut  oak  tree  are  cut 
into  suitable  lengths,  say  about  four  feet  long,  in  the  forest. 
These  pieces  are  then  carried  to  the  factory,  where  they  are 
further  reduced  by  "chipping"  by  a  machine  built  especially 
for  the  purpose.  This  machine  is  a  cast  steel  disk  four  feet  in 
diameter,  revolving  rapidly  and  carrying  a  suitable  arrangement 
of  knives,  which  cut  the  wood  into  small  chips.    These  chips 

(74) 


TANNING  EXTRACTS. 


75 


are  carried  to  the  leaches  and  leached  or  extracted  as  is  usual 
in  tanneries.  No  chemicals  should  be  used  in  the  leaches. 
The  liquor  is  then  run  into  settling  tanks,  and  next  passed 
through  ten  wire  cloth  strainers  of  the  finest  meshes  to  clarify 
it,  after  which  the  liquor  goes  to  the  vacuum  pan  and  is  con- 
centrated under  diminished  pressure  at  a  temperature  of  be- 
tween 120°  and  1 400  F. 

The  above  described  method  of  settling  and  straining  is  the 
one  in  common  use  in  the  United  States,  and  it  produces  a 
liquor  which  is  pure  and  transparent  enough  to  be  made  into 
an  extract  suitable  for  tanneries. 

When  the  degree  of  heat  has  been  carried  too  high  in  the 
leaches,  such  liquor  can  only  be  clarified  sufficiently  by  1st. 
Lowering  the  temperature  below  the  coagulating  point  of  blood 
and  adding  blood;  2nd.  Raising  the  temperature  of  the  liquor 
sufficiently  high  to  coagulate  the  blood,  which  gathers  up  the 
fine  suspended  matter  and  settles  to  the  bottom  of  the  vat  or 
tank,  and  is  then  still  further  strained.  It  is  then  concentrated 
as  usual. 

Extract,  however,  made  from  a  liquor  which  has  been  pro- 
duced at  too  high  a  degree  of  heat — although  clarified  by  blood 
albumen — will  not  produce  a  satisfactory  article;  that  is,  such 
an  extract  is  not  strictly  speaking  a  concentrated  liquor. 

The  extract  maker,  it  is  true,  obtains  a  larger  yield  or  num- 
ber of  pounds  of  finished  extract  from  his  material ;  but  it  is  at 
the  expense  of  the  tanner.  The  excessive  degree  of  heat  in  the 
leaches  extracts  not  only  non-tanning  substances,  which  are 
objectionable,  but  destroys  also  certain  bodies  which  act  favor- 
ably in  the  production  of  leather. 

In  the  concentration  of  the  liquor  in  the  vacuum  pan  extreme 
caution  must  be  observed  as  to  the  degree  of  heat.  A  temper- 
ature of  over  1400  F.  or  thereabouts  produces  a  change  in  the 
tanning  substances  and  in  its  allied  non-tanning  substances, 
which  is  very  objectionable,  and  which  produces  an  undesir- 
able leather,  not  only  in  color  but  in  quality.  In  other  words 
a  liquor  although  carefully  made,  when  subjected  in  the  pan  to 


76 


THE  MANUFACTURE  OF  LEATHER. 


a  degree  of  heat  in  excess  of  1400  F.  or  thereabouts,  yields  an 
extract,  which,  when  diluted  with  water,  is  not  what  it  was  be- 
fore concentration.  It  is  on  this  account  that  the  multiple 
vacuum  pans — that  is,  more  than  one  pan — can  not  successfully 
be  used  in  the  concentration  of  liquors  or  the  making  of  ex- 
tracts. 

In  the  use  of  extracts  the  tanner  should  always  be  on  the 
lookout  for  only  the  pure  article,  free  from  adulterations  of  any 
kind.  Extract  is  now  being  used  extensively  for  sole,  upper, 
belting,  harness,  union,  enameled  and  patent  leather,  and  in 
nearly  all  the  cases  which  have  fallen  under  our  observation 
giving  good  results  in  both  tannage  and  weight. 

There  are  various  methods  followed  in  the  preparation  of 
hemlock  extract,  but  that  used  by  a  prominent  extract  com- 
pany in  Pennsylvania  is  a  good  one.  The  bark -is  ground  in 
the  old-fashioned  mill,  and  is  very  carefully  leached  in  the  old- 
fashioned  way  and  boiled  down  in  the  vacuum  pan  under  the 
least  degree  of  heat  that  can  be  employed.  No  chemicals 
whatever  are  used.  They  do  not  press  or  crush  their  bark  to 
get  from  it  a  larger  yield,  but  are  doing  their  best  to  give  a 
pure  article  which  will  produce  a  pure,  strong,  old-fashioned 
liquor.  They  take  a  good,  fresh  io°  barkometer  liquor  and 
boil  it  down  to  27^2°  Baume  in  vacuum.  There  is  no  other 
description  than  this,  for  this  is  all  they  do. 

The  boiling  point  of  water  varies  according  to  the  pressure. 
With  a  pressure  of  29.2  inches,  it  boils  at  21 2°;  with  a  pres- 
sure of  27.74  inches  it  boils  at  2080  F.  In  a  vacuum  water  will 
boil  at  670  F.  Advantage  is  taken  of  this  fact  in  the  extrac- 
tion of  sugar.  The  application  of  heat  in  the  ordinary  way 
converts  a  large  quantity  of  crystallizable  sugar  into  an  un- 
crystallizable  state,  thus  causing  a  serious  loss.  By  effecting 
the  concentration  in  a  vacuum  it  takes  place  in  a  much  lower 
temperature  and  prevents  this  source  of  loss. 

The  manufacture  of  tanning  extracts  now  closely  resembles 
the  process  for  extracting  sugar;  the  sliced  wood  is  exhausted 
by  diffusion  in  autoclaves  under  slight  pressure,  and  the  liquor 


TANNING  EXTRACTS. 


77 


is  filter-pressed  and  evaporated  in  some  cases  in  triple-effect 
apparatus  which  differs  from  those  used  at  the  sugar  works 
merely  in  being  constructed  entirely  of  copper  and  bronze,  to 
the  exclusion  of  iron,  and  in  being  worked  at  a  higher  vacuum 
than  sugar  pans  are.  Most  manufacturers  decolorize  the  liquor 
before  concentration,  either  by  the  addition  of  some  metallic 
salt  or  with  albumen  and  bisulphite  of  soda.  In  the  former 
case  the  acid  of  the  salt  remains  in  the  extract,  and  in  the 
latter  sulphate  of  soda  and  non-coagulable  albuminoids  are 
retained,  whilst  in  both  cases  tannin  is  necessarily  precipitated. 
The  presence  of  salts  in  tanning  extracts  is  much  to  be  depre- 
cated, since  they  accumulate  in  the  tan  pits  to  the  detriment  of 
the  leather. 

Roy  has  shown  that  the  so-called  decolorizing  processes  are 
beneficial  to  the  extract,  not  because  they  eliminate  coloring 
matters,  for  they  do  this  in  a  very  minor  degree,  the  color  of 
the  liquor  after  treatment  being  but  slightly  diminished  if  esti- 
mated on  the  basis  of  equality  of  tannin  content — but  because 
they  precipitate,  together  with  the  first  portions  of  tannin, 
certain  earthy  and  metallic  bases,  such  as  lime,  magnesia, 
manganese,  iron  and  copper,  derived  from  the  wood  and  from 
the  apparatus.  It  is  these  foreign  matters  which  arc  taken  up, 
combined  with  tannin,  by  the  leather,  imparting  bad  color  and 
harsh  and  brittle  grain.  By  substituting  an  aqueous  solution 
of  potassium  ferrocyanide  for  the  precipitate  previously  used, 
Roy  has  succeeded  in  removing  these  metallic  compounds 
without  appreciably  decolorizing  the  extract,  and  finds  that 
the  leather  produced  by  the  treated  extract  is  in  every  way 
comparable  with  that  prepared  with  oak  bark  liquor  made  in 
the  tan-yard. 

It  follows  that  tanning  extracts  must  be  examined  for  salts 
of  the  alkalies  and  alkaline  earths,  and  for  metallic  compounds, 
and  valued  in  accordance  with  their  content  of  these,  as  well 
as  with  their  content  of  tannin. 


CHAPTER  VI. 


SOAKING  AND  SOFTENING. 

Where  it  is  possible  to  do  so,  the  hides  should  be  carried 
through  whole  until  the  tanning  process  is  completed  and  then 
cut  into  sides. 

The  hides  should  not  be  soaked  in  putrid  soaks,  as  valuable 
gelatine  is  thereby  destroyed — fresh  water  being  cheap. 

A  German  tanner,  speaking  of  soaking,  says  that  good  econ- 
omical practice  requires  great  care  to  be  taken  in  soaking 
hides.  He  uses  principally  cow-hides  averaging  60  to  70 
pounds  in  weight,  and  they  reach  him  salted.  He  says  that 
his  first  work  is  to  free  these  hides  from  dirt  and  salt.  Econ- 
omic methods  require  that  the  hide  should  not  be  handled 
oftener  than  is  absolutely  necessary,  and  this  can  only  be 
avoided  by  systematic  arrangements  as  to  the  progress  of  the 
various  stages.  Soaking  hides  in  wheels  with  a  constant  in  and 
out  flow  of  water  is  one  of  these  methods  which  is  supposed  to 
soften  and  cleanse  the  hide.  It  does  it,  but  alas,  too  much  so ! 
The  salt  has  so  acted  on  the  hide  that  its  most  valuable  con- 
stituents, which  are  very  soluble,  are  easily  washed  out,  espec- 
ially from  the  thinner  portions  of  the  hide,  which  will  show 
with  a  heavy  loss  in  the  finished  leather.  The  same  danger  is 
incurred  in  soaking  hides  in  the  common  tumbling  barrel, 
drum  or  wheel.  Better  results  are  obtained  from  a  wheel  di- 
vided into  four  compartments.  The  falling  and  heavy  beating 
of  the  hide  from  one  side  of  the  wheel  to  the  other  is  thus  pre- 
vented, and  the  movements  are  more  gentle  and  of  a  rolling 
nature.  The  simplest  and  best  method  is  soaking  in  a  water 
pit  or  box.  He  prefers  a  number  of  such  pits,  made  of 
masonry  and  cemented,  arranged  in  a  row.    Three  or  four  of 

(  78) 


SOAKING  AND  SOFTENING.  79 

such  will  be  enough  for  an  ordinary  tannery.  They  should  be 
arranged  with  a  waste  pipe  to  empty  them,  and  large  enough 
to  hang  the  hides  in  their  full  length.  The  hides  can  then  be 
transferred  from  one  pit  to  another.  Two  days'  soaking,  with 
four  changes  of  water,  is  sufficient  to  cleanse  the  hides  thor- 
oughly. Hanging  the  hides  is  better  than  throwing  them  in, 
as  it  saves  labor,  and  gives  them  a  more  even  soaking.  The 
best  plan  is  to  hang  the  hides  on  sticks  the  length  of  the  back 
bone,  low  enough  to  be  covered  by  the  water,  draw  the  plug 
every  twenty- four  hours,  rinse  off  salt  and  sediment  and  run  in 
fresh  water. 

Green  or  native  slaughtered  hides  cannot  be  too  soon  put 
into  work,  for  it  is  true  that  as  soon  as  life  ceases  decomposi- 
tion commences,  except  a  detergent  be  applied.  Salt  is  very 
generally  used  for  this  purpose,  and  is  effective,  although  not 
the  least  injurious  agent  that  might  be  used.  Some  have  a 
great  aversion  to  salt,  but  it  is  one  of  the  easiest  evils  to  remove. 
Borax  is  a  better  agent  than  salt  for  preserving  hides  and 
skins,  and  is  very  easily  removed  by  soaking. 

Dried  hides  and  skins  are  too  various  to  particularize,  and 
require  a  variation  in  soaking,  depilating  and  cleansing  from 
the  depilator  before  tanning  is  commenced,  if  a  good  return  is 
expected.  Green  hides  and  skins  should  first  be  well  cleansed 
from  dung,  dirt  and  any  extraneous  blood  there  may  be  re- 
maining on  them,  and  then  well  soaked  from  two  to  six  hours, 
according  to  the  kind  of  skin  or  hide. 

The  preparation  of  hides  and  skins  should  commence  by  first 
cleansing  them  from  dirt,  salt  and  blood  previous  to  using  any 
depilatory  process — more  especially  from  blood  or  albumen,  as 
they  deteriorate  all  kinds  of  leather  where  any  portion  is  left  in, 
and  prevent  a  full  expansion  of  the  fibrine,  which  should  be 
fully  extended  and  clean,  that  the  tannic  acid  may  have  free 
access  to  and  form  the  chemical  combination  with  it ;  salt  also 
should  be  thoroughly  eradicated  ;  then  we  have  the  hide  or  skin 
free  to  operate  on  for  depilation.  What  are  called  green  or  native 
hides  and  skins  are  very  frequently  saturated  with  salt  to  pre- 


8o 


THE  MANUFACTURE  OF  LEATHER. 


serve  them  in  transit  to  the  market,  or  to  keep  them  from  week 
to  week,  and  are  often  stored  by  the  tanner  previous  to  putting 
into  work.  These  are  generally  subjected  to  a  washing  in  pits. 
This  we  would  call  a  partial  cleansing,  but  not  an  eradication 
of  either  salt  or  blood,  although  a  gradual  decomposing  of  the 
pelt,  and  the  first  step  toward  reducing  the  quality,  weight  and 
profit. 

Foreign  salted  hides  and  skins  are  subjected  to  the  same 
kind  of  treatment,  but  for  a  longer  space  of  time,  and  from  the 
lengthened  time  they  have  been  in  salt,  which  has  extracted 
much  of  the  water  of  the  pelt,  it  does  not  act  so  quickly;  yet 
before  it  is  considered  fit  for  lime,  or  other  depilator,  the  same 
waste  commences  as  in  home  slaughtered  hides  treated  by  this 
mode. 

Dry  salted  hides,  kips,  etc.,  require  a  longer  time  to  get 
them  into  a  state  fit  for  the  depilatory  process.  These  are 
generally  put  into  a  pit  of  water  kept  for  the  purpose,  called  a 
soak,  and  used  from  time  to  time  until  it  becomes  quite  putrid. 
The  staler  it  is  the  more  effectively  it  softens  the  pelt,  but  often 
it  is  found  that  the  flanks  and  thinner  parts  are  damaged  or  de- 
composed before  the  stout  parts  or  shanks  and  heads  are 
rendered  as  soft  as  the  pelt  should  be  in  a  natural  state,  and 
must  be  made  before  liming,  etc. 

Dried  hides  and  skins  are  still  more  difficult  to  bring  back 
to  the  state  they  were  in  when  taken  off  the  animal,  because  of 
the  carelessness  in  drying  before  they  are  stored  or  packed. 
There  is  much  uncertainty  about  the  soundness  of  every  part 
of  the  hide.  Defects  do  not  show  themselves  till  put  into 
work ;  then  every  part  that  has  not  been  perfectly  dry  or  has 
been  tainted  before  drying,  will  appear  either  by  the  hair  com- 
ing off,  the  grain  peeling,  or  often  large  portions  of  the  hide 
rotting  away.  Even  when  the  hides  are  perfect,  the  soft  and 
thin  parts  are  damaged  by  decomposition  before  the  thick, 
hard  parts  are  nearly  soaked,  although  stocks  or  tumblers  are 
used  to  facilitate  the  softening ;  yet  three  or  four  weeks  are 
often  occupied  in  this  preparation  by  the  general  mode,  the 


SOAKING  AND  SOFTENING. 


8] 


uncertainty  of  which  causes  this  class  of  hides  to  be  much 
neglected  by  our  tanners,  though  they  should  be  the  most 
remunerative  in  our  trade,  the  leather  produced  from  them 
meeting  with  ready  sale.  Various  modes  for  improving  the 
preparation  of  this  class  of  hides  have  been  brought  forward, 
and  some  experiments  have  been  made,  but  there  has  not  been 
much  progress  in  this  direction. 

Dry  foreign  hides  and  skins  have  long  been  neglected  by 
tanners  on  account  of  the  difficulty  of  bringing  them  back  to 
the  soft  state  they  were  in  when  taken  off  the  animal,  and  the 
uncertainty  of  getting  the  whole  of  the  pelt  into  a  state  that 
will  make  leather.  This  arises  from  two  causes — first,  from 
the  hides  being  imperfectly  dried,  for  when  any  moisture  is  left 
in,  before  packing  for  transit  or  storing,  although  it  may  not  be 
observable  to  the  eye  of  the  purchaser,  they  will  rot  in  the 
soak,  and  be  worse  when  put  into  lime  or  other  depilator. 
Another  very  general  cause  is  that,  with  present  modes  of 
softening  by  stale  foul  soaks,  the  thinner  parts  are  deteriorated 
before  the  stout  parts  are  softened. 

The  tanner  has  no  control  over  the  first  cause  and  cannot 
guard  against  it  except  by  buying  at  a  price  that  will  allow  for 
these  defects  ;  but  the  latter  cause  may  be  avoided  if  a  suitable 
soaking  liquor  is  used.  This  has  been  accomplished  by  the 
aid  of  chemistry,  and  results  prove  that  the  foul  soak  may  be 
dispensed  with,  not  only  without  loss,  but  with  increased  profit. 
The  coarse  buffalo  will  yield  to  this  chemical  soak,  and  the  hard 
dry  calf  will  be  made  fit  for  glove  kid. 

While  speaking  of  this  important  part  of  preparing  the  hide 
or  skin  we  would  draw  attention  to  the  necessity  of  its  being 
done  thoroughly.  Too  much  care  cannot  be  taken  at  this 
stage,  for  if  the  pelt  is  not  fully  developed  it  cannot  be  rem- 
edied afterward.  Such  a  soak  should  be  used  that  no  danger 
is  to  be  feared  from  leaving  in  till  every  part  is  fit  for  the  de- 
pilatory process,  yet  the  weaker  parts  not  injured.  Stocks, 
drums  and  tumblers  are  a  great  acquisition,  but  chemical  aid 
united  to  mechanical  skill  crowns  the  whole. 
6 


82 


THE  MANUFACTURE  OF  LEATHER. 


The  usual  mode  of  softening  dry  hides  for  sole  leather  by 
putting  them  in  stale  old  soaks  is  very  offensive,  and  very  pre- 
judicial to  the  pelt,  as  most  tanners  know  to  their  cost.  Some 
lessen  the  risk  by  putting  them  through  stocks  or  tumblers ; 
but  many  tanners  still  do  without  the  aid  of  machinery  in  this 
part  of  the  preparation,  forgetting  that  the  longer  the  hide  is 
in  a  foul  soak,  the  less  weight  of  leather  will  be  realized, 
through  the  weaker  parts  exuding  their  gelatine.  This  is  one 
of  the  causes  of  old  soaks  being  so  offensive,  as  every  addition 
decomposes  and  increases  the  nuisance. 

We  would  recommend  a  chemical  soak  that  might  be  used 
with  or  without  the  aid  of  machinery,  although  stocks  or  tum- 
blers are  a  great  acquisition,  not  only  in  the  saving  of  time,  but 
in  preventing  loss,  for  the  more  quickly  a  hide  is  softened  the 
less  is  drained  out  of  it.  The  time  for  various  kinds  will  differ, 
but  from  our  own  observation  we  should  say  East  India  kips 
put  into  clean  water  over  night  may  be  softened  by  aid  of  ma- 
chinery in  three  hours  the  next  morning,  or  without  mechani- 
cal aid,  in  two  days  or  less,  dry  calf  in  proportionate  time.  Dry 
buffaloes,  soaked  in  the  same  way  twenty-four  hours,  we  have 
seen  well  softened  with  six  hours'  tumbling ;  still,  we  would  not 
place  too  much  value  upon  speed  alone.  We  should  remem- 
ber it  is  quality  and  weight  that  is  the  desideratum,  and  judg- 
ment must  be  used  to  get  the  hide  back  as  near  to  its  natural 
state  as  possible  before  it  touches  any  depilatory  composition 
or  liquor,  which  roughly  we  would  say  may  be  done,  from  calf- 
skin to  buffalo  or  dry  flint  hide,  in  from  six  hours  to  three  days. 

Dry  salted  skins  will  soak  more  regularly  than  skins  that  are 
simply  dried,  but  these,  where  machinery  is  not  used,  should 
be  well  worked  over  the  fleshing  beam  daily  until  they  are  in 
good  condition.  Plain  dried  skins  should  always  be  worked 
over  the  beam  after  the  first  few  hours'  soaking,  for  there  are 
many  folds  about  the  edges  that  even  with  machinery  will  not 
open  so  as  to  soften  properly  unless  this  is  done,  and  the  same 
may  be  profitably  practiced  with  green  home-slaughtered  hides 
and  skins,  for  where  they  are  dry  at  shanks  from  exposure  in 


SOAKING  AND  SOFTENING. 


83 


transit,  the  depilator  will  injure  and  not  act  properly.  These 
also  may  be  advantageously  put  into  a  chemical  soak  for  a  few 
hours,  to  prepare  them  for  the  depilating  liquor  or  compound. 

All  hides  and  skins,  if  not  bruised  by  tumblers  or  stocks, 
should  be  well  worked  over  the  fleshing  beam  till  the  loose 
flesh  is  thoroughly  softened  and  pulpy.  If  this  is  not  done  it 
is  impossible  for  the  pelt  to  progress  satisfactorily.  Some  say 
the  nerve  must  be  broken,  but  it  is  sufficient  if  the  veins  and 
membranes  are  so  softened  that  they  rise  from  the  true  skin. 
They  will  then  allow  the  liquors  to  pass  through  the  flesh  to 
be  easily  removed  after  unhairing. 

Borax,  as  is  well  known,  is  largely  used  in  laundries  for 
softening  the  water,  and  by  packers  for  preserving  meats.  It 
must,  therefore,  prove  an  invaluable  agent  to  tanners.  To 
soften  i.ooo  gallons  of  water,  five  pounds  of  borax  are  used. 
It  is  dissolved  in  boiling  water,  poured  into  the  vat  or  tank 
under  vigorous  stirring.  Borax  is  one  of  the  gentlest  of  the 
alkalies,  and  is  one  of  the  most  perfect  of  the  cleansers.  It 
is  equally  applicable  to  all  kinds  of  leather,  and  it  will  pay  all 
leather  manufacturers  to  use  it  in  their  soaks.  The  Pacific 
Coast  Borax  Co.,  New  York,  Chicago  and  San  Francisco,  are 
the  largest  producers  of  it  in  this  country. 

Borax  and  alum  in  combination  will  soften  very  hard  water, 
by  removing  all  the  mineral  matter  and  impurities,  leaves  the 
water  pure  and  soft.  Nearly  all  other  chemicals  and  compounds 
used  for  the  purification  and  softening  of  water  leave  traces  of 
their  presence  behind,  which  very  often  give  more  trouble  than 
the  primary  cause  which  it  was  sought  to  remove. 

By  using  pure  water  in  the  soaks  the  use  of  destructive 
chemicals  is  not  only  minimized  but  the  very  best  results  are 
obtained  at  much  less  cost  than  where  impure  water  is  em- 
ployed. At  a  cost  of  seven  cents  for  borax  and  alum,  one 
thousand  gallons  of  water  can  be  purified  and  made  soft. 

Most  natural  waters,  as  is  well  known,  contain  small  quanti- 
ties of  alkaline  salts  and  earth.  In  using  such  waters  for  swell- 
ing, cleansing  and  washing  the  hides,  the  swelling  influence 


84 


THE  MANUFACTURE  OF  LEATHER. 


which  these  salts  have  upon  the  coriin  must  be  taken  into 
consideration. 

In  hard  water  containing  much  of  these  salts  the  skins  must 
remain  for  a  shorter  time  than  in  soft  water,  that  is,  such  as 
contains  but  a  small  quantity  of  salts  or  none  whatever. 

Soaking  calf-kid  and  light  hides  depends  on  the  weather. 
Ten  hours  will  be  enough  if  the  chill  is  off  the  water.  Steam 
can  be  used  in  winter  time,  but  with  judgment. 

SOFTENING. 

It  is  usual  to  soften  dry  hides  and  skins  in  the  hide-mill 
after  they  come  from  the  soaks  and  have  been  divided  into 
"  sides,"  and  previous  to  subjecting  them  to  the  liming  process, 
and  the  time  which  they  are  worked  in  this  mill  depends  upon 
the  hardness  or  softness  of  the  hides  or  skins.  For  the  sides 
that  are  intended  to  be  worked  for  upper  leather,  the  usual 
time  is  from  one-quarter  to  three-quarters  of  an  hour,  while 
skins  that  are  intended  for  the  production  of  morocco  and  kid 
leathers  are  usually  worked  from  ten  to  twenty  minutes. 

The  construction  of  hide-mills  differs  greatly  for  the  various 
branches  of  leather  manufacture.  Those  employed  for  soften- 
ing hides  and  kips  are  similar  to  the  fulling  mills  common  in 
woolen  factories ;  while  the  mills  used  for  manipulating  skins, 
such  as  goat  and  sheep  skins  intended  for  the  production  of 
morocco  and  kid  leathers,  are  sometimes  in  the  form  of  a  large 
revolving  drum,  the  interior  of  which  has  a  number  of  oak  pins 
attached  securely  to  it,  and  so  arranged  as  to  soften  the  skins 
as  they  fall  upon  them,  or  in  other  ways  continually  come  in 
contact  with  the  pins.  The  number  of  skins  placed  in  a  mill 
of  this  kind  at  one  time  is  from  one  hundred  and  fifty  to  two 
hundred,  and  the  morocco  and  kid  tanners  where  it  is  used, 
call  it  a  "  pin-mill." 

The  morocco  and  kid  tanners  of  Philadelphia,  Penna.,  employ, 
sometimes,  a  softening  mill  for  the  dry  skins  of  a  very  different 
construction,  which  consists  of  a  central,  vertical,  or  upright 
shaft,  on  the  top  of  which  is  keyed  a  beveled-wheel,  which 


SOAKING  AND  SOFTENING. 


85 


meshes  with  a  suitable  pinion.  About  two  feet  above  the 
socket  in  which  the  upright  shaft  revolves,  and  passing  through 
and  secured  firmly  to  the  main  shaft,  is  a  second  shaft  about 
fourteen  feet  long,  and  extending  horizontally  at  right  angles 
with  the  upright  shaft  so  as  to  divide  itself  into  two  arms  of 
equal  length.  About  one  foot  from  the  end  of  each  of  these 
arms  there  is  an  iron  collar  secured  to  the  shaft,  and  against 
each  of  these  collars  a  large  granite  roller,  about  four  feet  in 
diameter  and  eight  inches  face,  is  rested,  the  ends  of  the  pro- 
jecting arms  of  the  horizontal  shaft  passing  through  the  centre 
of  the  stone  rollers,  which  are  held  in  place  by  large  iron 
washers  which  play  loosely  on  the  shaft  against  a  steel  pin. 

A  pit  is  excavated  about  three  feet  deep,  following  the  circle 
described  by  the  inside  vertical  face  of  the  two  stone  rollers. 

The  socket  in  which  the  main  or  upright  shaft  revolves  is 
placed  on  a  level  with  the  bottom  of  the  stone  rollers,  and  is 
supported  upon  a  pedestal  firmly  planted  in  the  centre  of  this 
circular  pit. 

A  workman  stands  in  this  pit  and  arranges  the  skins  under 
the  rollers  as  they  revolve,  sometimes  exposing  the  flesh  side 
and  at  other  times  the  hair  side  to  the  rollers,  and  all  the  while 
keeping  them  moistened  by  throwing  water  upon  them,  which 
he  obtains  from  the  bottom  of  the  pit  in  which  he  is  standing. 

Mills  of  this  kind  may  have  their  advantages  for  softening 
skins,  or  they  would  not  be  employed  by  some  of  the  largest 
morocco  and  kid  tanners  in  this  country;  but  they  are  in  our 
opinion  both  clumsy  and  dangerous,  as  it  is  simply  a  question  of 
time  when  one  or  both  hands  or  arms  of  the  workman  who 
attends  them  will  be  crushed  by  the  rapidly  revolving  stone 
rollers,  and  besides  the  skins  are  constantly  exposed  to  injury 
by  remaining  too  long  in  one  position  under  the  rollers. 


CHAPTER  VII. 


DEPILATION  OR  "  UNHAIRING." 

t 

LIME. 

A  DEPILATORY  is  any  substance  which  has  the  property  of 
removing  hair  from  hides  or  skins  without  injuring  the  texture. 

Some  skins  with  which  the  tanner  has  to  deal  are  depilous, 
that  is,  without  hair,  such  as  alligator  skins  and  skins  of  ani- 
mals of  the  lizard  family,  which  are  quadruped,  corticated  and 
depilous — that  is,  without  wool,  fur  or  hair. 

In  leather  manufacture  hides  and  skins  are  steeped  in  a  solu- 
tion of  lime  in  order  not  only  to  remove  the  hair,  but  at  the 
same  time  to  swell  the  hide  or  skin  ready  for  the  reception  of 
the  tanning  liquor. 

There  are  many  methods  for  accomplishing  the  depilation  or 
unhairing  of  hides  and  skins,  but  it  is  commonly  achieved  by 
placing  them  in  a  solution  of  lime  until  the  hair  bulb  is  loosened, 
thereby  allowing  the  hair  to  be  readily  rubbed  or  scraped  off. 

Lime  is  an  alkaline  earth  of  great  economic  importance.  It 
is  the  oxide  of  the  metallic  base  calcium,  but  neither  this  metal 
nor  its  oxide  occurs  in  nature  in  the  uncombined  condition, 
although  existing  in  enormous  quantity  in  various  combina- 
tions. Lime,  as  artificially  made  for  use  in  the  arts,  is  prepared 
by  calcining  limestone  or  marble,  or  seashells,  in  properly  con- 
structed furnaces,  known  generally  as  lime  kilns  or  simply  kilns. 
By  this  process  the  carbonic  acid  is  driven  off  from  the  lime, 
and  the  latter  remains  as  an  infusible  amorphous  substance, 
which  is  white  when  pure  limestone  has  been  employed.  In 
this  condition  it  is  commonly  known  as  quicklime.  When  ex- 
posed to  the  air  it  attracts  moisture  and  falls  into  powder  with 
greater  or  less  rapidity,  according  to  the  humidity  of  the  atmos- 

(86) 


DEPILATION  OR  "  UNHAIRING." 


87 


phere  and  the  quality  of  the  lime.  This  process  is  called  air- 
slaking.  Lime  for  tanners'  use  is  slaked  by  the  addition  of 
a  large  quantity  of  water,  which  is  absorbed  with  avidity  and 
with  considerable  evolution  of  heat. 

There  are  few  limestones  which  do  not  contain  a  greater  or 
less  quantity  of  sand  and  clay,  or  of  silicates  of  various  bases 
mixed  with  the  calcareous  material. 

The  lime  as  prepared  from  various  qualities  of  rocks  varies 
in  character  with  the  nature  and  amount  of  this  foreign  admix- 
ture. Limestone  containing  less  than  5  or  6  per  cent,  of  im- 
purities yields  a  rich  or,  as  it  is  often  called,  a  fat  lime.  With 
more  than  that  amount  the  lime  is  poor,  and  does  not  augment 
in  bulk  to  any  considerable  extent  when  slaked  with  water. 
The  rich  or  fat  lime  is  the  one  which  is  of  the  most  importance 
in  tanning. 

The  use  of  lime  is  often  inconvenient  and  in  many  ways  un- 
satisfactory, as  owing  to  the  energetic  action  which  free  lime 
exerts  on  animal  tissues,  a  considerable  portion  of  the  gelatin- 
ous tissue  of  the  hide  is  disintegrated  and  decomposed  during 
the  liming  process,  and  removed  from  the  hide  in  the  form  of 
soluble  gelatine,  or  else  so  altered  as  to  be  rendered  incapable 
of  combining  with  tannin,  thereby  incurring  a  serious  loss  in 
the  weight  of  leather  that  should  be  produced,  and  in  its  qual- 
ity, as  the  skins  or  hides  treated  by  this  process  produce 
leather  less  supple  and  more  brittle  than  is  desirable. 

These  objectionable  results  are  more  of  a  physical  than  of  a 
chemical  character;  the  principal  modifications  of  the  chemi- 
cal constitution  of  the  hide  or  skin  treated  by  the  lime  process 
are  the  slight  increase  in  the  quantity  of  lime  which  it  originally 
contained,  and  a  decrease  in  the  quantity  of  fatty  matters  due 
to  the  saponification  caused  by  the  lime  ;  the  harshness  and 
brittleness  imparted  to  the  leather  being  caused  not  only  by  the 
saponification  of  the  fatty  matters,  but  much  more  so  through 
the  presence  of  the  quantity  of  lime  which  penetrates  into  the 
tissues. 

Suppleness  being  an  indispensable  requisite  for  upper,  mo- 


88 


THE  MANUFACTURE  OF  LEATHER. 


rocco,  and  other  kinds  of  leather,  it  is  restored  to  them  after 
being  treated  by  the  lime  process  by  subjecting  them  to  the 
action  of  a  bating  process,  performed  by  immersing  the  hides 
or  skins  in  a  solution  of  hen,  pigeon  or  dog  manure,  bran,  coal 
tar  bate,  and  various  other  solutions,  the  object  of  such  treat- 
ment being  to  neutralize  the  lime  contained  in  the  tissues. 

This  "bating"  is  usually  performed  in  consequence  of  the 
employment  of  lime  for  depilating,  and  as  both  of  these  pro- 
cesses are  expensive  and  add  largely  to  the  cost  of  producing 
all  classes  of  pliable  leather,  it  is  much  to  be  desired  that  some 
substitute  for  lime  should  be  found  which  would  be  generally 
acceptable  to  tanners,  and  obviate  the  bating  process  as  well 
as  lessen  the  expense  of  unhairing  hides  and  skins. 

From  the  large  amount  of  attention  that  is  being  given  to  the 
subject  of  depilating,  both  in  this  country  and  in  Europe,  and 
from  the  tendency  of  the  age  to  cheapen  all  the  manufactured 
products  of  general  consumption,  we  are  probably  safe  in  say- 
ing that  the  time  is  now  near  at  hand  when  the  slow,  inconven- 
ient process  of  depilating  by  lime  must  be  succeeded  by  more 
effective,  rapid  and  economical  methods. 

Some  of  the  inconveniences  of  the  liming  process  we  recapit- 
ulate as  follows : 

1.  The  contact  of  caustic  lime  alters,  more  or  less,  the  texture 
of  the  hide,  and  permitting  it  to  penetrate  the  pores,  it  remains 
in  them  in  the  state  of  caustic  lime,  carbonate,  or  lime  soap. 

2.  The  rinsings  in  water,  bating,  and  the  workings  remove  it 
only  partially,  leaving  an  impediment  to  thorough  tanning. 

3.  It  also  hinders  the  ready  penetration  of  the  tan  liquor,  and 
the  perfect  combination  of  tannin  with  the  skin,  and  so  obsti- 
nately resists  removal  during  all  manipulations  that  a  portion  is 
always  found  in  the  best  leather. 

These  disadvantages  have  already  led  to  numerous  efforts  for 
the  substitution  of  other  agents,  which  we  shall  enumerate  later  on. 

The  present  process  to  which  hides  are  subjected  is  termed 
"  raising,"  and  by  it  the  pores  are  distended,  the  fibres  swollen, 
and  the  hair  loosened.    These  results  are  effected  by  means  of 


DEPILATION  OR  "UNHAIRING." 


89 


alkaline  or  acid  solutions,  and  by  sweating  or  fermentation. 
Milk  of  lime,  as  we  have  stated,  is  the  alkaline  liquor  generally 
employed.  Lime  water  has  been  proposed  as  a  substitute,  but 
it  is  less  permanent  in  its  action,  and  requires  frequent  renewal 
in  order  to  insure  the  perfect  cleansing  of  hides. 

The  primitive  manner  of  removing  the  hair  was  to  shave  it 
off,  but  lime  was  employed  even  by  the  early  Egyptians.  The 
depilating  process,  in  addition  to  swelling  the  hide,  thereby 
loosening  the  hair  and  disposing  it  to  yield  readily  to  the  de- 
pilatory operation,  also  facilitates,  by  opening  the  pores,  the 
absorption  of  the  tannin. 

If  there  be  a  desire  to  tan  quickly,  and  produce  good  and 
heavy  leather,  it  is  highly  important  that  the  hides  or  skins 
should  be  properly  prepared  in  the  beam  house.  As  the  after 
results  depend  largely  upon  the  intelligent  care  bestowed  here, 
much  more  attention  should  in  practice  be  given  than  most 
tanners  are  inclined  to  grant. 

All  hides  that  are  intended  for  limed  stock  should  be  put  in 
the  right  condition  for  the  lime — that  is,  soft  enough,  but  not 
flaccid,  as  dried  skins  may  be  greatly  injured  by  being  softened 
too  much.  A  hide  fresh  from  the  animal  is  the  best  criterion 
as  to  the  condition,  for  in  that  state  it  is  best  suited  for  the  lime. 

When  placed  in  the  lime  they  should  be  frequently  handled 
or  agitated,  and  should  remain  in  the  solution  no  longer  than 
may  be  necessary  to  loosen  the  hair  in  order  that  it  may  be 
readily  removed. 

The  ancients  and  those  whom  progress  has  failed  to  reach, 
said  and  the  latter  say  still,  "Who  limes,  tans."  Any  tanner 
who  entertains  such  ideas  tans  his  stock  without  a  thought  of 
the  difficulties  he  is  creating  for  the  currier. 

Lime  is  a  factor  at  the  same  time  useful  and  hurtful,  and  it 
therefore  becomes  necessary  that  the  tanner  should  occupy 
himself  actively  with  the  conduct  and  the  good  management  of 
his  lime  pits,  and  he  should  in  case  of  necessity  entrust  this 
work  only  to  a  reliable  man,  a  good  workman. 

Most  tanners  neglect  their  work  at  the  lime  pits,  and  when 


90 


THE  MANUFACTURE  OF  LEATHER. 


our  American  calfskin  tanners  fully  realize  this  point,  take  care 
of  their  lime  pits,  and  see  to  the  intelligent  beam  work  of  their 
stock,  they  will  produce  calfskins  of  the  first  quality,  for  we 
possess  better  bark  for  this  work  than  can  be  found  in  Nor- 
mandy or  any  portion  of  France. 

We  shall  diverge  for  a  moment  and  speak  of  the  proper  treat- 
ment of  calfskins  in  the  limes.  When  the  slaughtered  calfskins 
peel  they  should  be  immediately  taken  out  of  the  lime.  After 
having  allowed  them  to  drip  well,  put  them  in  a  vat  with  enough 
water  to  cover  them  without  floating.  They  thus  undergo  a 
first  disgorging.  They  may,  if  necessary,  remain  in  this  water 
for  eight  or  ten  days  without  spoiling.  This  method  is  prefer- 
able to  piling,  for  while  in  the  water  the  skins  disgorge  and  the 
action  of  the  lime  is  weakened,  while  in  the  pile  the  lime  con- 
tinues its  action,  and  if  workmen  in  piling  are  not  careful  to 
open  them  evenly  the  skins  get  what  the  curriers  call  "  lime 
folds,"  which  are  almost  impossible  to  eradicate  in  currying. 
But  best  of  all,  as  soon  as  the  skins  peel  take  them  out  of  the 
lime  pits,  rinse  them  and  unhair  them  at  once,  as  promptness 
in  the  execution  of  labor  is  an  economy  of  capital.  From  this 
first  stage  the  work  must  go  on  as  fast  as  possible. 

Salted  calfskins,  after  being  properly  soaked,  should  be  put 
into  the  dead  lime  pit,  and  afterward  treated  the  same  as 
slaughtered  stock  from  this  point;  but  the  dry  skins  require  a 
milder  lime  liquor  than  the  salted  skins  and  the  fresh  slaugh- 
tered stock.  This  work  is  thus  rendered  a  little  slower  on 
account  of  the  lime  liquor  in  the  dead  lime  pit  having  been 
previously  carefully  weakened. 

Lime  in  depilating  has  been  at  times  replaced  by  acid  liquors, 
but  their  employment  requires  the  exercise  of  judgment.  The 
dilute  mineral  acids  make  the  hair  yield  easily,  but  at  the  same 
time  they  swell  and  soften  the  hide  too  much,  so  that  the  use 
of  organic  acids  is  preferable.  In  some  tanneries  lime  is  re- 
placed by  a  mixture  of  slacked  lime  and  ashes.  Through  the 
mutual  action  of  the  lime  and  the  carbonate  of  potassium  a 
caustic  alkali  is  formed,  which  operates  more  energetically. 


DEPILATION  OR  "  UNHAIRING." 


91 


Lime  vats  are  constructed  either  of  timber  or  of  masonry, 
and  in  tanneries  where  hides  are  worked  they  are  sunk  into  the 
ground  so  that  the  tops  of  the  vats  are  on  a  level  with  the  floor 
of  the  beam-house,  but  in  goat  and  sheep  skin  tanneries  the 
vats  are  partly  below  and  partly  above  the  level  of  the  floor. 

The  vats  destined  to  swell  the  hides  to  facilitate  the  depila- 
tion  and  raising  are  usually  constructed  so  as  to  take  sides  in- 
stead of  whole  hides,  the  hides  being  usually  split  after  soaking, 
which  answers  for  upper  leather ;  but  it  is  very  much  better  for 
the  stock  that  is  intended  for  sole,  belt  and  harness  leather,  to 
lime  the  whole  hides,  and  then  if  they  are  not  carried  through 
all  the  processes  of  tanning  to  split  them  into  sides  after  the 
liming. 

When  split  previous  to  liming,  the  thin  portions  of  the  hide, 
shoulders,  etc.,  contract  to  a  much  greater  degree  than  the 
butts  and  other  thicker  portions,  and  consequently  the  back 
line  is  irregular,  which  would  not  be  so  noticeable  if  the  lime 
had  uniform  action  on  the  whole  hide,  thus  economizing  the 
waste  in  cutting  sole  and  harness  leather,  but  more  especially 
belt  leather,  where  straight  back  lines  are  very  desirable. 

The  number  of  hides  determines  ordinarily  the  quantity  of 
lime  necessary  for  each  vat.  To  make  a  new  vat,  throw  into 
into  it  unslacked  lump  lime,  cover  with  water  gradually  so  as 
not  to  drown  it,  and  stir  well  with  a  stirrer  until  slacked  and 
reduced  to  the  consistence  of  milk.  This  operation  completed, 
leave  it  until  it  is  ready  to  receive  the  hides.  Usually  the  lime 
is  prepared  in  a  hogshead,  and  from  this  poured  into  the  vat, 
care  being  observed  to  retain  the  sediment  in  the  bottom  of  the 
hogshead,  which  keeps  the  lime  vats  cleaner  and  is  beneficial 
in  many  respects.  The  vats  are  distinguished  as  dead,  weak 
and  live  vats,  and  sometimes  as  old  and  fresh  limes.  The  dead 
or  old  vat  is  that  which  has  been  frequently  used  and  which 
has  been  nearly  exhausted  of  its  strength ;  the  weak  is  that 
which  has  been  used  long  enough  to  deprive  it  of  a  portion  of 
its  force,  and  the  live  or  fresh  vat  is  that  which  has  not  yet 
been  worked. 


92 


THE  MANUFACTURE  OF  "LEATHER. 


It  is  easy  to  understand  that  the  live  vat  becomes  success- 
ively the  weak  and  the  dead  vat.  When  a  tanner  uses  more 
than  three  vats  he  establishes  between  the  dead  and  the  live 
vats  as  many  middling  term  vats  as  convenient,  and  the  whole 
of  the  vats  are  called  the  raising  series. 

The  raising  should  be  commenced  in  the  dead  vat,  and  con- 
tinue in  consecutive  order  through  the  series  to  the  live  vat. 
In  some  tanneries  in  Europe  the  series  consists  of  twelve  or 
more  vats,  and  in  that  case  there  should  be  a  graduation  in  the 
strength  of  the  liquors.  The  duration  of  this  operation  varies 
in  different  localities,  as  in  all  portions  of  Europe  the  hides  are 
limed  for  a  longer  period  than  with  us. 

The  practice  is  still  in  vogue  among  some  tanners  of  using 
old  limes  which  are  charged  with  the  decomposing  matter  ex- 
tracted from  previous  packs,  which  practice,  in  warm  weather, 
becomes  extremely  hazardous. 

The  time  usually  employed  for  liming  different  classes  of 
hides  and  skins  will  later  on  be  mentioned  in  chapters  devoted 
to  the  manufacture  of  sole,  upper,  calf,  kid  and  other  leathers. 

The  power  reel  is  now  generally  employed  for  handling  sole 
leather  hides  in  the  lime  vats,  and  it  is  the  most  economical, 
convenient  and  effective  method,  the  sides  being  strung  to- 
gether and  passed  over  the  reel  from  vat  to  vat. 

American  tanners  put  hides  through  the  soaks  and  limes  in 
about  four  days.  During  the  last  twelve  hours  of  this  period 
the  packs  lie  in  hot  water.  The  hides  are  reeled  three  or  four 
times  during  the  first  day  in  limes  ;  then  reeled  twice  on  the 
following  day  from  vat  to  vat.  All  kinds  of  fancy  schemes 
have  been  tried  for  lessening  the  destruction  of  hide  substance 
in  the  beam-house,  but  tanners  still  stick  to  simple  handling, 
strong  limes,  hot  water  and  short  time.  By  this  method  75  to 
80  per  cent,  of  acid  hemlock  sole  leather  has  been  made  from 
plump,  well-grown,  heavy  Texas  steers,  fall  kill.  This  is  good 
showing,  and  it  is  results  that  count  in  this  busy  world. 

Every  intelligent  tanner  knows  that  no  exact  or  arbitrary 
rules  can  be  given  for  liming  and  handling  any  kind  of  hides 


DEPILATION  OR  "  UNHAIRING. 


93 


or  skins,  as  the  time  required  varies  greatly,  being  dependent 
on  kind  and  condition  of  the  skins,  condition  of  atmosphere, 
temperature,  and  temperature  of  the  limes  in  use,  etc. 

In  the  liming  of  goat  skins  it  is  customary  to  add  about  one 
and  a  half  pounds  of  arsenic  to  each  bushel  of  lime. 

The  "arsenic"  used  is  sulphide  of  arsenic,  and  when  mixed 
with  lime  forms  sulphide  of  lime.  This  acts  upon  the  skin 
vigorously,  hastens  the  unhairing,  and  is  supposed  to  give  the 
skin  a  finer  grain  than  when  lime  is  used  alone.  This  sulphide 
of  lime,  however,  penetrates  to  all  parts  of  the  skin,  and  when 
present  in  excess  does  not  become  thoroughly  removed  in  the 
subsequent  operations  of  washing,  bating,  etc.  So  an  excess  of 
arsenic  is  injurious  and  would  have  a  tendency  to  make  the 
grain  tight  and  dry  so  as  to  cause  skins  to  crack. 

Skins  left  too  long  in  old  limes  are  apt  to  have  the  grain 
somewhat  plumped,  and  the  pores  very  open,  as  though  not 
worked  out  sufficiently. 

The  grain  being  loose  from  the  flesh  is  a  common  occurrence, 
and  results  from  a  variety  of  causes.  It  indicates  that  some 
solution  into  which  skins  have  been  placed  was  too  powerful. 

There  is  no  way  to  tell  to  a  certainty  whether  or  not  a  skin 
has  been  sufficiently  limed  ;  only  long  familiarity  with  the  class 
of  skins  and  their  appearance  in  this  state  would  enable  one  to 
form  a  correct  judgment. 

Manufacturers  of  kid  are  devoting  much  attention  at  the 
present  to  the  "cellar"  or  "beam-house"  department  of  their 
works.  These  gentlemen,  having  mastered  the  new  chrome 
process  of  tanning,  are  now  striving  to  effect  economies  and 
improvements  in  liming  and  bating. 

Before  any  real  improvements  can  be  made,  it  is  most 
essential  to  understand  just  what  it  is  necesssry  to  accomplish 
by  these  two  important  operations,  and  to  recognize  the  fact 
that  rough  crude  processes  which  would  doubtless  give  good 
results  on  sole  leather  are  entirely  unsuitable  for  kid  stock 
where  the  final  operation,  in  finishing,  is  glazing.  Roughly 
speaking,  the  use  of  lime  is  for  the  purpose  of  removing  the 


94 


THE  MANUFACTURE  OF  LEATHER. 


hair,  and  the  operation  of  bating  for  the  purpose  of  removing 
lime  from  the  stock  preparatory  to  tanning.  If  this  was  all  to 
be  accomplished,  the  operations  would  be  comparatively- 
simple,  but  in  the  manufacture  of  glazed  stock  other  important 
results  are  necessary  to  success. 

Lime  and  dog-pure  have  been  used  in  the  beam-house  for 
many  years;  both  are  objectionable  and  have  disadvantages, 
yet  owing  to  their  long  use  experience  has  taught  the  workmen 
their  properties,  and  they  know  just  about  how  to  deal  with 
them  in  order  to  attain  the  desired  result.  Any  other  materials 
which  could  be  used  in  place  of  these  articles  would  doubtless 
bring  new  and  unlooked  for  difficulties  and  would  require 
changes  in  the  methods  of  working  in  order  to  make  their  use 
a  success. 

Lime  acts  upon  the  roots  of  the  hair ;  the  hair-sheaths  are 
dissolved,  thus  enabling  the  hair  to  be  removed  on  the  beam, 
the  hair  itself  being  but  slightly  altered.  The  effect  of  lime 
upon  the  skin  itself  is  most  marked,  and  it  is  the  action  of  the 
lime  other  than  the  removal  of  the  hair,  which  is  most  import- 
ant in  the  preparation  of  stock  for  glazed  kid.  Lime  acts 
vigorously  upon  the  true  skin ;  the  fibres  swell  and  absorb 
water,  so  the  skins  become  plump  and  swollen  and  at  the  same 
time  the  cement-like  substance  (coriin),  which  glues  the  fibres 
together,  is  dissolved  and  the  fibres  become  differentiated  into 
finer  fibrils  and  so  open  up  the  skin,  so  to  speak,  in  order  that 
it  may  tan  evenly  and  properly.  Another  action  of  the  lime  is 
upon  the  natural  fat  or  oil  of  the  skin,  converting  it  into  a  more 
or  less  insoluble  soap,  which  is  largely  removed  in  the  subse- 
quent operations  to  which  the  stock  is  subjected.  These  re- 
sults therefore  are  necessary  to  accomplish  by  the  liming 
operation. 

In  the  liming  of  sheepskins  consideration  should  always  be 
given  to  the  removal  of  the  grease.  This  is  most  economically 
done  by  a  wringer.  Some  large  concerns  also  use  presses  for 
this  purpose,  and  some  imported  sheepskins  which  have  been 
unhaired,  fleshed  and  split,  are  soaked  in  naptha.    For  making 


DEPILATION  OR  "UNHAIRING." 


95 


up  a  fresh  lime  for  a  4x5x6  feet  vat,  holding  about  900  gallons 
of  water,  for  liming  190  to  200  large  sheepskins,  there  should 
be  use  five  or  six  pails  of  stone  lime.  Strengthen  next  day  with 
three  or  four  pails  of  stone  lime.  High  liming  may  kill  some 
little  grease,  but  not  sufficient  to  make  first-class  leather  from 
greasy  sheepskins.  Sulphur  and  lye  in  correct  proportions  will 
not  hurt  the  skin,  but  we  prefer  to  use  commercial  sulphide  of 
sodium  for  strengthening  the  limes.  If  lye  and  sulphur  be 
mixed  in  definite  proportions  they  will  in  time  combine  and 
form  sulphide  of  sodium.  The  fresh  pulled  skins  can  be  entered 
directly  into  the  new  lime;  it  would  be  useless  to  first  dilute 
with  water,  but  it  will  be  found  that  an  older  lime  will  make  a 
better  leather  than  a  new  lime.  It  cannot  be  told  by  cutting 
a  skin  whether  or  not  it  has  enough  lime.  Let  the  limes  run 
into  the  sewer  and  thoroughly  clean  vat  about  every  two  months. 
Some  of  the  clear  liquor  from  this  lime  that  is  run  off  should 
be  used  to  make  up  a  new  lime  again. 

What  can  the  disease  known  as  the  itch  possibly  have  to  do 
with  the  liming?  The  itch  is  a  skin  disease  caused  by  a  para- 
site lodging  under  the  skin  of  the  living  animal.  We  shall  see 
in  the  course  of  this  chapter  why  we  speak  of  the  itch  in  con- 
junction with  liming.  It  is  a  fact  that  a  large  percentage  of  all 
skins  suitable  for  glove  kids  are  more  or  less  scabby.  This  is 
very  troublesome  because  for  the  delicate  shades  only  such 
skins  can  be  employed  as  have  a  perfectly  healthy  grain,  while 
scabby  skins,  if  not  too  badly  disfigured,  can  be  used  only  for 
very  dark  colors,  sometimes  also  for  white  or  straw  color.  If 
the  grain  is  badly  disfigured  the  skins  must  be  finished  into 
undressed  kid.  A  further  objection  to  scabby  skins  is  that  be- 
sides the  disfigurements  the  quality  of  the  skin  has  severely 
suffered.  In  bad  cases  even  an  inexperienced  buyer  will  notice 
the  trouble,  but  the  more  hidden  symptoms  are  difficult  to  no- 
tice even  by  experienced  men.  The  extent  of  this  disease  may 
be  judged  from  the  fact  that  pretty  nearly  50  per  cent,  of  all 
lambskins  on  Continental  markets  are  scabby.  The  main  diffi- 
culty is  found  in  the  fact  that  although  most  frequent  in  the 


96 


THE  MANUFACTURE  OF  LEATHER. 


coarser  grades,  this  disease  is  also  quite  general  among  the 
very  highest  grades  of  skins.  Thus  in  France  the  skins  of 
suckling  goats  of  unequaled  quality,  of  which  a  dozen  are  worth 
$10.00  in  the  hair,  are  scabby  to  the  extent  of  more  than  35 
per  cent.,  so  that  often  the  front  half  cannot  be  used  for  gloves. 
It  requires  very  experienced  skin-buyers  in  order  to  get  as  little 
scabby  stock  as  possible.  It  seems  strange  that  otherwise 
healthy  animals  should  be  affected  with  this  skin  disease  at 
their  birth.  This  is  due  to  the  fact  that  the  disease  is  inherited 
from  generation  to  generation.  This  disease  manifests  itself 
in  principally  two  different  forms,  the  prominent  and  the 
hidden  form.  Many  tanners,  especially  lambskin  tanners, 
recognize  also  a  third  form  which  they  call  the  "  white  itch." 
The  prominent  form  is  readily  recognized  even  by  inexperienced 
eyes,  as  the  scabby  spots  have  often  penetrated  the  entire 
thickness  of  the  skin  from  the  grain  to  the  flesh,  or  at  any  rate 
are  readily  seen,  particularly  in  the  flanks,  by  holding  the  skin 
against  the  light.  They  then  appear  as  dark  spots.  The 
hidden  form  is  present  only  under  the  grain.  On  the  white 
glove  kid  this  form  can  hardly  be  noticed,  but  on  colored 
stock  it  is  very  prominent.  This  form  of  the  itch  causes  all 
colors,  especially  the  delicate  shades,  to  look  clouded  and  dirty. 
Skins  in  the  hair  afflicted  with  this  hidden  form  of  disease  can 
be  picked  out  only  by  men  of  considerable  experience  by 
means  of  the  general  appearance  and  symptoms  of  such  skins. 
The  third  form,  or  white  itch,  consists  of  a  peculiar  disfigure- 
ment of  the  grain,  which  latter  looks  as  if  it  were  covered  in 
places  with  granulated  sugar.  This  white  itch  is  not  the  result 
of  any  disease,  however,  but  consists  of  fine  crystals  of  alum 
and  salt  deposited  on  the  grain.  Only  recently  a  lot  of  skins 
that  were  thus  disfigured  were  sent  for  investigation  to  Der 
Gerber,  of  Vienna.  They  inquired  into  the  details  of  the  man- 
ufacture of  this  particular  lot  of  skins,  and  found  that  the  cause 
of  this  white  effloresence,  known  as  white  itch,  was  the  result 
of  using  a  deficiency  of  lime  and  too  much  arsenic  in  the  limes. 
This  prevented  a  sufficient  loosening  of  the  skin  and  the  result 


DEPILATION  OR  "  UNHAIRING. 


97 


was  that  the  alum  and  salt  used  for  tanning  were  imperfectly 
absorbed. 

DEPILATING  WITH  SODIUM  SULPHIDE. 

During  the  past  twenty  years  much  has  been  wrilten  and 
many  experiments  have  been  conducted  with  a  view  to  the  in- 
troduction of  sodium  sulphide  as  a  depilatory.  At  the  present 
time,  however,  it  is  generally  conceded  by  all  progressive  tan- 
ners to  be  an  exceedingly  useful  article  in  the  beam  house  treat- 
ment of  hides  and  skins.  Prof.  Eitner,  in  Germany,  Prof.  Proc- 
tor, in  England,  and  Prof.  Fiebing,  in  America,  have  indorsed 
it  as  a  valuable  material  when  properly  used,  and  have  recom- 
mended various  methods  for  its  application  in  the  unhairing  and 
swelling  of  hides  and  skins.  The  consensus  of  opinion  now  is 
that  to  obtain  the  best  results  from  the  use  of  sodium  sulphide 
lime  should  be  used  in  connection  with  it.  When  lime  is  added 
to  a  solution  of  sulphide,  the  latter  unites  with  the  calcium  to 

•  form  calcic-sulphydrate  and  at  the  same  time  liberates  caustic 
soda,  which  considerably  increases  the  unhairing  and  plumping 

i  effect.  A  similar  reaction  takes  place  when  the  red  arsenic  is 
mixed  in  a  solution  of  lime,  a  sulphydratc  of  lime  being 
formed,  which  is  the  active  agent  in  producing  the  desired 
effect.  The  use  of  arsenic  sulphide  in  this  way  has  been  favor- 
ably known  to  tanners  from  very  early  times,  but  a  substitute 
for  this  expensive  and  exceedingly  poisonous  material  is  found 
in  the  sodium  sulphide,  which  is  much  cheaper  and  just  as 
effective.  It  is  now  an  established  fact  that  the  sulphydrate  of 
lime  does  not  dissolve  out  so  much  of  the  hide  substance  as 
when  the  lime  alone  is  used,  and  being  quicker  and  more  ener- 
getic in  its  action,  both  time  and  space  are  economized  in  the 
tannery  by  its  use. 

Prof.  Fiebing,  in  writing  upon  this  subject,  says,  "that  the 
action  of  lime  is  throughout  solvent  and  swelling,  and  more 
actual  hide  substance  is  probably  lost  by  pure  liming  than  by 
any  other  unhairing  process.  The  solvent  action  of  an  old  and 
fresh  lime  is  nearly  the  same,  while  the  swelling  property  de- 
7 


98 


THE  MANUFACTURE  OF  LEATHER. 


creases  with  age.  A  material  that  is  steadiiy  though  slowly 
gaining  in  favor  is  sulphide  of  sodium.  This  substance,  though 
not  new,  is  but  litde  understood  by  the  trade.  One  disadvan- 
tage of  lime  for  unhairing  hides  intended  for  any  leather  where 
a  certain  degree  of  solidity  and  filling  are  desired,  is  its  prop- 
erty of  dissolving  the  corii'n  faster  than  it  will  properly  loosen 
and  distend  the  fibres.  Consequently,  if  we  lime  long  enough 
to  properly  prepare  the  hides  for  the  liquor,  considerable  loss 
of  weight  will  inevitably  follow  by  reason  of  the  solution  of  a 
large  amount  of  corii'n.  If  a  short  liming  is  resorted  to,  the 
fibres  cannot  be  properly  loosened,  and  a  flat,  tinny  leather  is 
liable  to  be  the  result.  Now,  we  have  in  sulphide  of  sodium  a 
material  that  will  efficiently  counteract  this  undesirable  property 
of  lime.  Sulphide  of  sodium  will  loosen  and  split  up  the  fibres 
much  quicker  than  lime,  and  if  used  in  proper  proportions  will 
not  dissolve  as  much  corii'n  as  lime.  By  combinations  of  these 
two  depilatories  we  can,  therefore,  obtain  an  excellent  unhair- 
ing agent  for  almost  any  kind  of  leather." 

The  method  of  using  the  sulphide  in  connection  with  lime, 
as  recommended  by  those  who  have  been  most  successful  with 
it,  is  to  dissolve  from  one-half  to  three-quarters  of  a  pound  to 
each  hide,  and  mix  it  with  about  the  same  weight  of  lime  pre- 
viously slacked.  This  is  thrown  in  the  pit  with  sufficient  water 
to  cover  the  hides  and  the  hides  suspended  in  the  solution.  By 
this  method  of  suspension  the  action  of  the  depilatory  is  much 
more  uniform  than  when  the  hides  are  thrown  loosely  into  the 
pit.  The  length  of  time  required  for  the  unhairing  and  the 
distending  and  separating  of  the  fibres  will  depend  upon  the 
firmness  and  flexibility  desired  in  the  leather.  For  sole  leather 
from  one  to  two  days  should  be  amply  sufficient,  while  for 
upper  leather  a  longer  time  would  be  necessary.  The  same 
kind  of  mixed  depilatory  may  be  used  with  advantage  upon 
calfskins  and  goatskins,  though  in  this  case  the  skins  may  be 
agitated  and  their  position  changed  by  the  use  of  a  paddle 
wheel  attached  to  the  pit,  and  thereby  a  uniform  action  of  the 
depilatory  be  obtained.    There  are  several  grades  of  sulphide 


DEPILATION  OR  "  UNHAIRING." 


99 


of  sodium  now  offered  in  the  market,  varying  in  their  degree 
of  purity.  The  common  salts  occur  as  crystals  of  a  deep- 
greenish-black  color,  and  are  contaminated  by  iron  sulphide, 
which  produces  dark  blue  stains  on  the  hides  and  skins.  A 
better  sort  is  found  in  an  amber-colored  crystal  which  is  com- 
paratively free  from  iron.  The  crystals  of  sodium  sulphide 
contain  69  per  cent,  of  water  and  are  very  deliquescent,  and  the 
material  should,  therefore,  be  kept  in  a  dry  place  and  from 
exposure  to  the  air.  A  new  and  concentrated  form  of  sodium 
sulphide,  free  from  iron  and  free  from  water,  has  recently  been 
introduced  by  the  Martin  Dennis  Chrome  Tannage  Co.,  of 
Newark,  N.  J.,  who  state  that  it  is  more  than  twice  as  strong  as 
the  ordinary  sulphide  crystals  and  of  purer  quality.  It  would 
seem  that  this  form  of  sulphide  should  recommend  itself  to 
tanners,  because  many  of  the  objections  urged  against  the  older 
form  of  the  material  are  removed. 

The  advantages  obtained  by  the  use  of  sodium  sulphide  may 
be  enumerated  as  follows  : 

1.  The  unhairing  and  swelling  of  the  hides  or  skins  is  ac- 
complished more  quickly,  thereby  saving  both  time  and  space 
in  the  tannery. 

2.  The  swelling  and  distending  of  the  fibres  is  not  attended 
by  so  great  a  loss  of  hide  substance  as  when  lime  alone  is  used, 
thereby  insuring  plump  and  full  leather  with  a  minimum  loss 
of  weight. 

3.  The  hair  and  epidermis  are  so  thoroughly  loosened  that 
the  unhairing  operation  may  be  conducted  in  a  wash  wheel, 
thus  saving  the  labor  of  beam  work. 

4.  The  sulphydrates  being  more  soluble  than  pure  lime,  it 
follows  that  the  depilating  material  can  be  removed  from  the 
hides  or  skins  easily,  quickly  and  inexpensively  by  mere  wash- 
ing with  water.  In  fact,  it  is  claimed  by  some  that  if  the  wash 
water  is  used  warm,  about  8o°  to  900  F.,  no  bating  will  be  re- 
quired, especially  in  case  the  hides  are  intended  for  sole 
leather. 

Upon  these  and  many  other  considerations  it  seems  safe  to 


IOO 


THE  MANUFACTURE  OF  LEATHER. 


predict  that  sodium  sulphide  will  be  more  and  more  favorably 
recognized  by  tanners  as  a  valuable  and  almost  indispensable 
material  in  the  art  of  leather  manufacture,  and  that  the  future 
will  bring  it  into  much  more  general  use  than  at  present. 

This  material  is  also  very  largely  used  for  wool  pulling. 

Sodium  sulphide  is  a  crystallized  chemical  substance  of 
definite  and  regular  composition.  Any  competent  chemist  can 
determine  its  strength.  Its  value  as  a  depilatory  depends  solely 
upon  the  amount  of  monosulphide  of  sodium  which  it  contains, 
and  not  upon  any  patent  or  so-called  improvement  whatever. 
One  hundred  pounds  of  crystal  sulphide  of  sodium  contain  be- 
tween thirty-one  and  thirty-three  pounds  (31  and  33  percent.) 
monosulphide  of  sodium.  For  the  convenience  of  consumers 
the  dealers  in  sulphide  of  sodium  guarantee  this  product  to 
contain  at  least  31  per  cent,  of  monosulphide  of  sodium,  and 
if  desired,  will  furnish  a  chemist's  certificate  to  that  effect. 

Ordinary  sulphide  of  sodium  is  frequently  sold  under  a  fancy 
name  at  a  higher  price  than  it  is  worth. 

Tanners  are  also  offered  a  so-called  "  improved  "  sulphide  of 
sodium,  wherein  the  "  improvement  "  consists  in  adulterating, 
or  weakening,  or  cheapening  it  with  common  sulphate  of  soda, 
an  article  worth  on  the  market  less  than  half  a  cent  a  pound. 

Both  of  these  arc  impositions.  Fortunately  they  can  be 
easily  detected. 

The  late  John  W.  Stevens  says  of  the  sulphide  of  sodium 
process : 

"Tanners  who  are  making  specialty  of  imitation  goat,  book- 
binding or  pocketbook  leather,  wherein  the  leather  is  split 
down  to  a  very  light  substance,  should  not  go  too  extensively 
into  this  process  until  after  several  experiments  have  been 
made  with  the  sodium,  and  then  by  using  it  in  a  mild  form,  for 
the  following  reasons:  By  the  use  of  sulphide  of  sodium  a 
thicker  grain  is  produced  than  by  the  use  of  lime  and  hen 
manure,  and  when  split  down  to  a  very  light  substance  the 
grain  becomes  tender.  Again,  leather  suited  for  imitation  goat 
finish  must  have  a  thin  grain  to  produce  the  desired  character 


DEPILATION  OR  "  UNHAIRING." 


IOI 


and  prominence  in  che  print.  When  too  thin,  it  would  be 
found  difficult  to  throw  up  a  figure  in  the  cork  boarding  to  re- 
semble the  real  goat  skins.  In  all  other  respects  the  quality  of 
the  leather  is  superior,  being  of  a  tougher  fibre,  finer  flanks 
and  of  a  supple  and  elastic  nature,  so  desirable  for  fine  shoe 
leather. 

"  For  boot  and  shoe  oil  grains,  glove  grain  and  imitation 
calf,  where  the  grain  is  buffed  off  in  finishing,  the  sulphide  of 
sodium  process  is  especially  adapted,  as  also  for  slaughter  sole, 
oak  and  union  crops  and  backs,  which  are  also  submitted  to 
the  buffing  operation  to  produce  a  uniform  finish  and  light 
color  to  the  soles  when  made  into  shoes.  This  process  will 
also  be  of  great  value  to  tanners  making  sole  and  upper  leather 
from  dry  flint  hides.  There  will  always  be  found  in  this  class  of 
hides  many  that  are  sunburnt,  particularly  those  coming  from 
Africa  and  South  America,  and  it  is  a  difficult  matter  to  work 
them  in  warm  weather.  To  soak  them  sufficiently  long  to 
bring  the  hide  back  to  its  original  condition,  putrefaction  would 
set  in,  and  unless  the  hides  are  made  pliable  before  going  into 
the  lime,  all  subsequent  labor  is  lost  in  the  endeavor  to  produce 
plump  and  heavy  leather.  For  a  soak  of  fifty  whole  hides  in- 
tended for  upper  leather,  and  averaging  some  twenty  pounds 
eaeh,  dissolve  one  pound  of  the  sulphide  of  sodium  in  hot 
water  and  pour  into  the  pit,  previously  filled  with  cold  water: 
mix  thoroughly  with  plunger  and  throw  in  the  hides.  This  has 
a  tendency  to  not  only  preserve  the  hides  during  the  soaking, 
but  will  soften  up  the  sunburned  portions  and  greatly  facilitate 
the  unhairing  process  at  a  later  stage.  After  being  immersed 
two  or  three  days,  pull  up  the  hides  and  examine  their  condi- 
tion. Those  that  have  yielded  more  readily  to  the  water  and 
sodium  throw  aside,  and  carry  them  along  by  first  milling  in 
the  wash-wheel  without  water  until  a  friction  is  created  and  the 
former  rigid  feeling  broken  ;  then  let  into  the  wheel  a  bounteous 
supply  of  water  until  the  hides  are  practically  freed  from  blood, 
dirt  and  manure,  when  they  will  be  in  good  condition  for  flesh- 
ing.   The  balance  of  the  pack,  should  the  hides  show  no  sign 


102 


THE  MANUFACTURE  OF  LEATHER. 


of  putrefaction,  may  be  thrown  back  into  the  soak  again  after 
lying  in  pile  a  few  hours  to  partially  sweat  them,  when  they  will 
soften  more  readily  in  the  solution.  It  will  not  be  necessary  to 
run  off  this  solution,  but  fill  the  pit  again  with  clear  water  until 
the  entire  pack  is  soaked.  If  in  cold  weather,  and  the  water  is 
cold,  the  same  may  be  used  with  some  replenishing  of  water  and 
the  sodium  for  several  successive  packs,  as  the  ammonia,  blood 
and  filth  accumulated  will  facilitate  the  soaking  of  dry  flint 
hides ;  but  care  must  be  taken  that  this  may  not  be  carried  too 
far,  and  that  the  hides  be  pulled  out  frequently,  and  then  select 
out  such  as  yield  more  readily.  For  sole  hides  of  greater  aver- 
age weight,  add  one-third  to  one-half  more  of  the  sodium  in  the 
soaks,  and  treat  in  the  same  way,  being  careful  not  to  use  such 
a  quantity  as  will  loosen  the  hair  too  freely  while  in  the  soaking 
process,  else  a  loss  of  weight  would  ensue  when  the  hides  are 
later  on  immersed  in  the  sodium  and  lime  solution  for  completely 
removing  the  hair.  For  soaking  dry  kips  and  calf-skins,  a  com- 
paratively small  amount  of  sodium  per  skin  would  be  required, 
and  may  be  regulated  by  the  average  weights,  although  skins 
of  finer  texture  require  a  stronger  solution  to  effect  the  desired 
object  than  do  heavy,  coarse  hides." 

The  use  of  sulphide  of  sodium  as  a  depilating  agent  is  very 
simple.  A  definite  quantity  being  weighed  off,  it  is  dissolved 
in  a  certain  amount  of  warm  water.  After  some  stirring  the 
solution  is  perfected.  It  is  of  brown  color  and  clear.  It  will 
not  deposit  on  standing,  and,  therefore,  need  not  be  stirred  be- 
fore use.  The  solution  will  not  ferment,  and  can  therefore  be 
kept  for  an  unlimited  length  of  time.  The  density  of  this  solu- 
tion is  of  no  importance ;  but  it  is  advisable  to  take  twenty 
quarts  of  water  for  every  pound  of  sulphide  of  sodium.  Ac- 
cording to  the  amount  of  hide  worked  in  per  day  we  must  make 
up  a  larger  or  smaller  quantity  of  the  solution.  The  solution 
can  be  made  up  in  a  cask  or  barrel.  It  is  imperative  to  know 
the  concentration  of  this  solution,  i.  c,  we  must  know  how 
much  sulphide  of  sodium  is  contained  in  every  quart  or  gallon 
of  the  solution.    We  recommend  a  concentration  of  one  pound 


DEPILATION  OR  "  UNHAIRING."  IO3 

of  sulphide  of  sodium  for  twenty  quarts  of  water.  If  we  add  to 
a  lime,  say,  three  pounds  of  sulphide  of  sodium,  which  quantity 
is  about  sufficient  for  an  ordinary  lime  holding  about  800  to 
1,000  lambskins,  according  to  size  of  the  skins,  we  must  take 
sixty  quarts  of  above  solution.  It  is  not  rational  to  add  this 
entire  quantity  at  once  to  the  lime,  but  it  should  rather  be 
given  in  three  or  four  portions,  adding  a  portion  every  other 
day.  For  every  portion  of  sulphide  of  sodium  solution  given 
we  should  add  one  bucket  of  slacked  lime.  The  slacked  lime  is 
dissolved  by  stirring  with  cold  water,  and  the  requisite  quantity 
of  sulphide  of  sodium  is  added  thereto.  This  mixture  is  then 
added  to  the  limes,  and  the  latter  thoroughly  plunged.  In 
making  up  a  fresh  lime  no  sulphide  of  sodium  is  added  at  first, 
in  order  to  give  the  skins  a  chance  to  plump.  After  the  first 
hauling  of  the  skins  the  fresh  lime  is  strengthened  with  above 
mixture  of  slacked  lime  and  sulphide  of  sodium,  and  this  mix- 
ture is  added  for  each  subsequent  strengthening.  As  regards 
the  relative  proportion  of  sulphide  of  sodium  necessary  to  ac- 
complish the  same  work  as  arsenic,  the  quantities  of  both  ma- 
terials are  identical,  /'.  c,  one  pound  of  sulphide  of  sodium  will 
do  the  same  work  as  one  pound  of  arsenic,  and  vice  versa. 

For  an  ordinary  lime  containing  about  800  to  1,000  lambskins 
(according  to  size),  we,  therefore,  need  three  pounds  of  arsenic 
or  else  three  pounds  of  sulphide  of  sodium.  The  solution  of  the 
arsenic  can  be  accomplished  by  mixing  some  with  lime  at  the 
time  of  slacking  and  thoroughly  stirring.  This  arsenic-lime 
paste  can  also  be  kept  for  a  long  time  without  spoiling,  and 
can,  therefore,  be  made  up  in  a  sufficient  quantity  to  last  for  a 
month  or  so.  Of  course,  the  quantity  of  arsenic  contained  in 
a  quart  or  a  gallon  of  the  paste  must  be  carefully  noted.  An- 
other way  of  dissolving  the  arsenic  is  by  vigorously  stirring  it 
with  milk  of  lime  for  about  half  an  hour  or  until  the  brown 
color  of  the  mixture  has  acquired  a  steel-gray  coloration.  This 
mixture  is  then  mixed  with  milk  of  lime  previously  diluted  with 
hot  water.  The  hot  water  materially  aids  the  solution  of  the 
arsenic.    The  first  method  of  solution  is,  however,  preferable. 


104 


THE  MANUFACTURE  OF  LEATHER. 


The  most  striking  effect  of  sulphide  of  sodium  in  the  limes 
is  its  property  of  bringing  back  the  grain  to  its  fresh,  green 
state,  even  if  the  skins  or  hides  have  become  withered  by 
reason  of  long  storage.  No  other  depilatory  agent  brings 
about  this  effect — even  arsenic-lime  will  not  restore  to  the 
grain  its  natural  green  freshness.  What  we  mean  by  speaking 
of  a  withered  state  of  the  grain  is  probably  not  clear  to  the 
majority  of  tanners.  To  be  sure  they  have  noticed  that  some- 
times the  grain  of  the  skins  appears  clouded,  while  at  other 
times  it  is  clear  after  unhairing ;  but  they  have  never  investi- 
gated the  cause  of  this  fact.  Now,  the  best  way  to  understand 
just  what  we  mean  is  to  make  the  following  experiment :  Take 
three  skins  as  near  alike  as  possible  and  unhair  one  in  the  or- 
dinary lime,  the  next  in  a  lime  strengthened  with  arsenic,  and 
the  third  with  sulphide  of  sodium.  Unhair  at  the  same  time 
and  spread  out  alongside  of  each  other,  and  note  the  wonder- 
ful difference  in  the  appearance  of  the  grain.  The  one  limed 
with  pure  lime,  particularly  if  the  limes  are  not  fresh,  will  show 
a  yellowish-gray,  clouded  grain  ;  the  grain  of  the  skin  limed  in 
the  combination  of  arsenic  and  lime  will  appear  clouded  and  of 
bluish-gray  color,  being  more  pronounced  the  older  the  limes  ; 
while  the  last  skin,  unhaired  with  sulphide  of  sodium,  will 
have  a  clear,  fresh  grain,  closely  resembling  in  appearance  a 
green  skin  after  liming.  As  we  know,  those  skins  that  are 
worked  in  fresh  from  the  slaughter  house,  are  perfectly  clear 
and  very  clean  on  the  grain  after  liming. 

Now  how  is  this  property  of  sulphide  of  sodium  explained  ? 
Let  us  first  note  the  fact  that  the  longer  a  skin  has  been  stored 
the  more  noticeable  is  the  clouded  appearance  of  the  grain  after 
unhairing,  and,  vice  versa,  the  fresher  a  skin  is  worked  in,  the 
clearer,  fresher  and  cleaner  is  the  grain.  What  is  the  cause  of 
this  cloudiness?  It  is  due  to  the  substances  originally  held  in 
solution  by  the  blood  and  lymph  of  the  animal,  which  have 
gradually  dried  out  on  the  grain,  becoming  more  insoluble  the 
longer  the  skin  is  stored,  until  eventually  they  have  become 
totally  insoluble  in  water.    The  fact  that  the  impure  juices  of 


DEPILATION  OR  "  UNHAIRING."  1 05 

the  blood  can  be  deposited  in  considerable  quantities  on  the 
grain,  can  be  readily  observed  on  the  skins  and  hides  of  dis- 
eased animals.  Every  tanner  knows  that  the  criterion  of  dis- 
eased skins  is  a  remarkable  cloudiness  of  the  grain,  and  that 
this  cloudiness  can  even  be  diffused  throughout  the  entire  skin 
to  the  flesh  side.  Sometimes  not  alone  the  juices  of  the  blood, 
but  the  blood  itself,  can  become  deposited  on  the  grain.  This 
can  be  clearly  seen  on  the  skins  of  animals  which  have  died 
from  disease,  which  invariably  show  blood  spots,  and  the  flesh 
side  of  which  has  a  dull  appearance.  Now  that  we  have  found 
the  cause  of  the  clouded  appearance  of  the  grain  to  be  due  to 
the  deposited  matter  of  the  blood,  we  must  next  endeavor  to 
discover  the  means  of  bringing  back  this  deposited  matter  to  a 
soluble  form.  For  this  purpose  sulphide  of  sodium  is  without 
a  rival.  The  dry  blood  albumens,  etc.,  are  so  completely  dis- 
solved by  sulphide  of  sodium  that  the  grain,  after  unhairing 
with  this  depilatory,  is  so  bright  and  clean  as  is  otherwise  only 
observed  in  green  butcher  stock.  Another  valuable  property 
of  sulphide  of  sodium  is  that  it  docs  not  dissolve  the  hide  sub- 
stance to  any  extent  if  employed  at  ordinary  strength.  It  can 
be  used  in  quite  concentrated  solutions  without  danger,  and  it 
matters  little  if  the  skins  are  left  in  longer  than  necessary.  Both 
the  hide  proper  and  the  grain  are  usually  tough  and  strong  if 
unhaired  with  sulphide  of  sodium.  Let  us  sum  up  the  good 
qualities  of  sulphide  of  sodium  : 

1st.  Tough  and  strong  leather,  particularly  of  the  grain. 

2d.  Closed  fibre,  well  filled  leather. 

3d.  Bright,  glossy  grain. 

But  sulphide  of  sodium  also  possesses  some  very  undesirable 
qualities.  We  have  remarked  that  sulphide  of  sodium  does  not 
dissolve  the  hide  substances  to  any  extent.  This  property  is  a 
decided  advantage  in  some  classes  of  leather,  but  for  glove- 
kid  it  is  extremely  undesirable.  Every  tanner  knows 
that  in  order  to  prod  ucc  plump,  stretchy  and  good-feeling 
glove-kid,  he  must  remove  a  certain  amount  of  hide  substance 
from  the  skins  by  means  of  the  depilatory  employed.    Now  as 


io6 


THE  MANUFACTURE  OF  LEATHER. 


sulphide  of  sodium  does  not  possess  this  solvent  property,  it 
follows  that  by  its  use  we  cannot  achieve  satisfactory  results  for 
glove-kid.  Sulphide  of  sodium  plumps  the  stock  similar  to 
vitriol.  In  concentrated  solutions  it  possesses  extraordinary 
plumping  qualities.  The  hair  bulbs  are  speedily  dissolved. 
In  fact  we  can  depilate  a  dry,  unsoaked  skin  with  a  very  con- 
centrated sulphide  of  sodium  solution  inside  of  a  few  hours; 
the  skin  will  swell  up  to  five  times  its  natural  thickness,  and  the 
hair  will  be  loosened  sufficiently  without  dissolving  any  hide 
substance.  If  by  this  process  we  treat  a  skin  that  has  pre- 
viously been  properly  soaked,  the  same  operations  will  be  per- 
formed inside  of  a  few  minutes.  This  fact  led  tanners  to  be- 
lieve that  sulphide  of  sodium  would  be  an  excellent  depilatory 
for  glove-kid  without  the  addition  of  lime,  but  experiments 
soon  showed  that  something  was  lacking,  and  now  sulphide  of 
sodium  is  never  alone  employed  for  depilating  glove-kid  or 
alum  leather.  If  sulphide  of  sodium  be  employed  for  any  class 
of  glove  or  upper  leather,  we  must  always  use  sufficient  lime 
with  it  to  dissolve  the  necessary  amount  of  hide  substance. 
Generally  not  enough  lime  is  used  with  sulphide  of  sodium  and 
the  result  is  flat  leather;  further,  the  skins  are  not  equalized, 
i.  e.,  that  thick  skins  remain  thick  and  thin  skins  remain  thin. 

It  is  another  undesirable  property  of  sulphide  of  sodium  that 
glove-kid,  made  from  skins  depilated  with  this  material,  get 
hard  and  unelastic  during  the  requisite  aging.  We  know  by 
experience  that  alum  tawed  glove-kid  must  age  a  certain 
length  of  time  in  order  that  the  tawing  materials  can  properly 
unite  with  the  fibre.  We  also  know  by  experience  the  result 
if  this  aging  is  not  properly  done  and  the  leather  goes  to  the 
dyer  too  fresh.  If  the  skins  are  colored  before  having  had  the 
requisite  time  of  aging,  the  tawing  substance,  being  only  loosely 
held,  will  be  washed  out  to  such  an  extent  as  to  result  in  a 
hard,  hungry  leather.  The  necessary  time  required  for  this 
aging  is  at  least  two  months,  and  need  never  exceed  twelve 
months.  A  naturally  mild  leather  skin  requires  only  a  two 
months'  aging,  while  a  flat,  hard  skin  necessitates  from  eleven 


DEPUTATION  OR  "  UNHAIRING."  107 

to  twelve  months  aging  before  coloring.  If  sulphide  of  sodium 
has  been  employed  as  a  depilatory  we  must  shorten  the  time 
of  this  aging  to  the  detriment  of  the  leather,  for  above  mentioned 
reasons.  This  disagreeable  property  of  leather  unhaired  with 
sulphide  of  sodium  becoming  hard  during  the  aging  is  due  to 
the  same  cause  as  the  flatness  of  this  leather.  A  green  skin  is 
flat  and  unelastic  as  compared  to  well-tanned  leather.  Why? 
The  naturally  loose  fibrous  network  is  pasted  together,  so  to 
say,  in  its  own  gelatinous  hide  substance,  which  latter  has  the 
property  of  getting  harder  the  more  the  skin  dries  out.  The 
depilating  process  must  remove  a  certain  amount  of  this  gela- 
tinous hide  substance,  and  the  spaces  so  formed  must  be  filled 
by  the  tawing  materials  which  give  to  the  leather  mildness, 
body  and  good  feel.  Inasmuch  as  sulphide  of  sodium  docs  not 
remove  an  adequate  part  of  this  gelatinous  hide  substance,  it  is 
natural  that  the  resulting  leather  somewhat  resembles  the  green 
skin  in  its  property  of  getting  hard  when  it  dries  out  completely 
and  remaining  flat.  Another  bad  property  of  such  leather  is 
the  difficulty  of  coloring  it,  which  is  also  due  to  the  presence  of 
too  much  of  the  gelatinous  hide  substance.  To  sum  up,  we 
can  obtain  a  good-looking  glove  kid  with  sulphide  of  sodium, 
but  it  must  be  quickly  sold  and  at  low  prices.  Manufacturers 
who  endeavor  to  establish  a  reputation  for  their  goods  cannot 
use  sulphide  of  sodium  for  making  glove  kid. 

A  writer  in  Dcr  Gerber  says :  If  the  practical  tanner  were 
satisfied  to  obtain  "similar"  effects  to  those  produced  by  arse- 
nic and  for  some  reason  wanted  to  replace  the  latter  by  a  sub- 
stitute, he  would  find  sulphide  of  sodium  best  adapted  for  the 
purpose.  But  there  is  a  tremendous  difference  between  "simi- 
lar" effects  and  identical  effects.  It  is  now  about  twenty  years 
ago  that  the  first  experiments  were  made  with  sulphide  of 
sodium  in  the  tannery,  and  it  seemed  for  a  time  that  a  material 
had  been  found  which  would  entirely  replace  the  poisonous 
arsenic.  After  numerous  and  careful  experiments  had,  how- 
ever, been  concluded  on  all  classes  of  hides,  from  the  heaviest 
sole  leather  down  to  the  most  delicate  glove  kid,  it  was  seen 


io8 


THE  MANUFACTURE  OF  LEATHER. 


that  although  admirably  adapted  for  some  purposes,  sulphide 
of  sodium  was  not  a  good  substitute  for  arsenic  in  all  cases. 
These  tests  brought  out  the  specific  properties  of  both  materials, 
and  thus  showed  us  for  which  grades  of  leather  arsenic  and  for 
which  sulphide  of  sodium  should  be  used  to  obtain  best  results. 
Thus  we  find  that  sulphide  of  sodium  is  used  to  this  day  in  the 
manufacture  of  sole  leather  and  to  some  extent  in  the  manufac- 
ture of  upper  leather  and  morocco  leathers,  for  which  classes 
of  leather  a  close  fibre  and  absence  of  elasticity  are  required. 
It  is  a  fact  that  also  some  glove  kid  manufacturers  still  employ 
sulphide  of  sodium,  but  these  are  only  those  manufacturers  who 
strive  to  turn  out  large  quantities  of  leather  in  the  shortest  pos- 
sible time,  irrespective  of  quality,  and  who,  therefore,  sell  for 
less  than  their  competitors.  For  this  latter  class  of  manufac- 
turers sulphide  of  sodium  is  admirably  adapted,  as  it  produces 
a  clean  grain  with  a  minimum  of  labor  ;  it  matters  little  to  them 
that  the  gloves  made  from  their  stock  often  get  hard  in  a  com- 
paratively short  time.  Manufacturers  of  glove  kid  who  warrant 
their  stock  to  remain  soft  for  a  long  time  cannot  employ  sul- 
phide of  sodium.  In  former  times  the  only  depilatory  known 
for  all  grades  of  leather  was  ordinary  lime.  In  the  course  of 
time  qualities  were  demanded  in  leather  that  could  not  be  ob- 
tained by  depilating  with  lime  alone.  The  main  requisite  de- 
manded of  a  depilatory  in  our  time  is  that  it  should  depilate 
evenly  and  quickly;  further,  it  should  thoroughly  remove  the 
fine  hair  and  cleanse  the  grain  and  skin  from  dirt,  and  above 
all  not  plump  the  hide  to  that  extent  peculiar  to  pure  lime.  It 
is  very  important  that  the  time  required  for  liming  the  hide  be 
shortened  for  many  grades  of  leather,  because  lime  dissolves 
considerable  hide  substance,  and,  therefore,  pure  liming  will 
not  produce  as  close  and  fine  a  leather  as  can  be  made  by 
using  some  other  depilatory.  Of  all  the  innumerable  depila- 
tories "discovered"  and  "invented"  of  late,  only  two  have 
come  to  stay,  viz.,  arsenic  and  sulphide  of  sodium.  Arsenic 
fulfills  all  requirements  of  a  depilatory,  as  above  enumerated,  if 
mixed  with  lime.    The  active  depilatory  agent  of  the  mixture 


DEPUTATION  OR  "  UNHAIRING." 


of  arsenic  and  lime  consists  of  several  different  combinations 
of  lime  and  sulphide  of  arsenic.  Both  the  sulphide  of  arsenic 
and  the  lime  have  lost  their  specific  properties  entirely  in 
these  combinations.  As  is  the  case  in  all  chemical  combina- 
tions, arsenic  sulphide  and  lime  will  combine  only  in  definite 
and  fixed  proportions.  An  excess  over  these  proportions  of 
arsenic  is  without  any  action  on  the  hide  or  hair,  as  it  is  insol- 
uble. An  excess  of  lime,  however,  will  act  as  such  on  the  hair 
and  hide.  As  in  practice,  where  arsenic  is  employed  in  com- 
bination with  lime,  there  is  always  an  excess  of  lime.  We 
really  have  two  different  depilatories,  viz.,  a  combination  of 
arsenic  with  lime,  and  pure  lime.  We  have  no  technical  word 
for  this  combination  of  sulphide  of  arsenic  with  lime,  excepting 
the  Arabian  word  "  Rusma,"  or  a  translation  of  the  German 
and  Austrian  tanners'  word  "Gift,"  designating  poison.  This 
combination  of  sulphide  of  arsenic  and  lime  has  some  very 
peculiar  properties,  foremost  among  these  being  the  property 
of  completely  eating  up  the  hair  in  very  short  time  to  a  pulpy 
mass.  This  property  gives  us  the  explanation  of  its  extraordi- 
nary depilating  power.  The  root  of  the  hair  being  the  soft- 
est part  of  the  hair,  this  depilatory  will  naturally  first  dissolve 
that  part,  and  with  this  solution  the  hair  will  give.  The  first 
requisite  of  a  depilatory — quick  action — is,  therefore,  fulfilled  by 
the  sulphide  of  arsenic  and  lime  combination.  Sulphide  of  so- 
dium in  this  first  effect  acts  identically  with  sulphide  of  arsenic 
and  lime.  It  also  eats  up  the  hair  in  a  very  short  time  and 
causes  it  to  give,  in  the  same  time  as  the  latter  depilatory.  Both 
depilatories  being  so  very  much  alike  in  this  respect,  it  was 
thought  at  first  that  this  would  also  be  the  case  in  all  other 
respects,  and  tanners  of  glove  kid  were  glad  to  be  able  to 
abandon  the  poisonous  arsenic.  But  they  soon  discovered  that 
other  properties  requisite  to  a  good  depilatory  for  glove  kid 
were  wanting  in  sulphide  of  sodium.  Besides  the  hair  proper, 
the  animal  hide  is  covered  with  a  short  down,  similar  to  what 
is  found  on  the  arms  and  legs  of  the  human  body.  This  down 
is  known  to  the  tanners  as  fine-hair.    In  the  process  of  unhair- 


IIO  THE  MANUFACTURE  OF  LEATHER. 

ing  a  large  proportion  of  these  fine-hairs  are  removed  by  the 
beamster,  providing  a  proper  loosening  of  these  fine-hairs  has 
been  accomplished  by  the  depilatory.  As  the  coarse  bulbs  of 
the  hair  are  loosened  in  shorter  time  than  the  bulbs  of  the  fine- 
hair  it  is  often  the  case  that  the  former  give  readily  on  the 
beam,  while  the  latter  are  still  held  very  firm,  and  can  be  re- 
moved only  with  difficulty  or  not  at  all.  It  is  no  trick  to  prop- 
erly loosen  the  hair  proper,  but  the  fine  points  of  depilating 
begin  with  a  proper  loosening  of  fine-hair,  and  it  is  here  that 
the  tanner  must  be  guided  by  experience  and  practical  tests  to 
know  when  the  depilatory  has  accomplished  this  result.  With 
lime  alone  the  fine-hair  may  be  removed,  but  pure  liming  will 
accomplish  this  only  after  the  soft  parts  of  the  grain  and  hide 
have  also  been  dissolved.  To  properly  remove  the  fine-hair 
by  pure  liming  without  the  aid  of  other  depilatories,  we  would 
have  to  employ  a  large  excess  of  lime  and  also  lime  consider- 
ably longer.  This  would  not  only  loosen  the  hide  too  much, 
making  it  spongy,  but  the  grain  would  be  deprived  of  its  gloss 
and  toughness  by  the  removal  of  its  most  juicy  constituents. 
It  is,  therefore,  necessary  to  loosen  the  fine-hair  by  employing 
some  substance  in  combination  with  lime  that  will  loosen  these 
finer-hairs  in  a  short  time  and  which  will  not  materially  attack 
the  hide.  Such  a  substance  we  have  in  the  combination  of  lime 
and  sulphide  of  arsenic.  Without  dissolving  the  soft  parts  of 
the  hide  and  without  disturbing  the  structure  of  the  hide  the 
arsenic-lime  acts  as  a  powerful  solvent  on  the  bulbs  of  the  hair 
and  fine-hair,  thus  loosening  them  in  a  very  short  time.  The 
rapidity  of  this  action  is  clearly  seen  by  painting  the  skins  with 
a  paste  of  arsenic-lime ;  such  skins  will  unhair  clean  in  as  many 
hours  as  it  would  take  days  to  do  the  work  by  liming  with  pure 
lime.  By  this  painting  process,  however,  we  employ  the  arsenic- 
lime  in  such  concentrated  state  as  would  not  be  possible  without 
injury  to  the  hide  in  the  limes.  Besides,  the  object  of  liming 
is  not  only  to  remove  the  hair,  but  also  to  bring  about  a  certain 
loosening  of  the  hide,  which  latter  cannot  be  accomplished  by 
the  arsenic-lime,  but  is  done  by  the  lime  alone.  Considering 


DEFLATION  OR  "  UNHAIRIXCi." 


I  I  I 


that  the  lime  must  be  allowed  a  certain  length  of  time  to  bring- 
about  a  proper  loosening  of  the  hide — eight  to  twelve  days — 
we  must  correspondingly  reduce  the  amount  of  arsenic-lime 
which  is  added  to  the  limes.  While  we  need  about  nine  pounds 
of  arsenic  together  with  enough  lime  to  form  a  paste  in  unhair- 
ing  by  the  painting  process,  we  take  only  about  two  and  one- 
half  pounds  of  arsenic  for  unhairing  in  the  limes  for  about  1 ,000 
medium  lambskins.  These  two  and  one-quarter  pounds  of 
arsenic  are  sufficient  to  bring  about  a  thorough  loosening  of 
the  hair  and  fine-hair  in  the  limes  in  about  eight  to  twelve  days. 
Of  course  if  we  have  particularly  heavy,  dry  skins  the  quantity 
of  arsenic  may  be  increased  about  half,  while  on  very  small 
delicate  skins  the  amount  should  be  reduced.  We  should  never 
use  much  above  the  requisite  quantity  of  either  arsenic  or  lime, 
i.  c,  only  enough  of  each  to  thoroughly  do  the  required  work. 
It  is  decidedly  wrong  to  believe  that  an  excess  of  lime  or  arse- 
nic will  not  harm,  for  a  large  excess  will  inevitably  destroy  the 
life  of  the  skin. 

Comparing  results  obtained  by  arsenic  with  those  obtained 
by  sulphide  of  sodium,  both  are  almost  identical  as  regards 
the  removal  of  the  hair  proper,  but  in  regard  to  the  loosen- 
ing of  the  fine-hair  there  is  a  big  difference  in  favor  of  the 
arsenic.  Practical  experience  has  shown  that  skins  unhaired 
in  limes  strengthened  with  sulphide  of  sodium  are  with  diffi- 
culty cleansed  of  their  fine  hair.  If  we  are  bound  to  employ 
sulphide  of  sodium  in  the  limes  we  must  take  considerably 
more  lime  than  where  arsenic  is  used,  or  else  we  must  take 
the  chances  of  injuring  the  grain  by  the  hard  work  neces- 
sary on  the  beam  to  remove  the  fine-hair. 

In  cleansing  skins  and  hides  from  foreign  matter  the  skin  01 
hide  has  always  been  regarded  as  a  unit,  i.  c,  grain  and  hide 
substance  has  been  regarded  as  one.  Careful  observation 
shows  us  that  this  is  not  correct;  the  study  of  the  difference 
in  results  obtained  with  sulphide  of  sodium  and  arsenic  espec- 
ially throws  considerable  light  on  this  subject.  The  animal 
hide  consists  of  several  dissimilar  parts. 


I  12 


THE  MANUFACTURE  OF  LEATHER. 


The  hide  is  made  up  of  the  fibro-cellular  tissue,  or  soft  albu- 
minous part,  the  muscular  fibres,  the  grain,  and  the  epidermis. 

The  epidermis,  or  extreme  outer  layer  of  the  hide,  is  again 
subdivided  into  the  soft  mucous  part  and  the  hard  horny  part. 

The  epidermis  may  be  regarded  as  a  cast-off  part  of  the  hide, 
which  we  need  not  here  consider. 

The  grain  of  the  hide  is  of  a  compact,  fine  and  firm  structure, 
while  the  true  skin  itself  is  softer,  looser  and  coarser  in  struc- 
ture. It  is,  therefore,  possible  to  properly  loosen  the  true  skin 
by  the  action  of  the  depilatory,  while  the  grain  will  not  be 
sufficiently  softened  and  cleansed.  The  contrary  may,  however, 
also  be  accomplished  ;  some  depilatories  will  soften  and  cleanse 
the  grain  in  comparatively  short  time,  while  the  true  skin  itself 
will  not  be  sufficiently  loosened  in  this  time.  It  is  of  frequent 
occurrence  that  leather  is  spongy,  loose  and  rotten  below  the 
grain,  while  the  grain  is  healthy  and  strong.  This  generally 
results  from  very  strong  pure  liming,  the  grain  having  resisted 
the  action  of  the  lime  longer  than  the  softer  true  skin.  On  the 
other  hand,  we  also  often  come  across  leather  of  which  the 
inner  parts  are  hard  and  brittle  while  the  grain  is  sound.  This 
inner  rottenness  is  due  to  the  insufficiently  dissolved  dirt;  it  is 
well  known  that  hard  rigid  leather  generally  has  the  most 
handsome,  bright  grain.  This  latter  case  is  the  result  of  insuf- 
ficient soaking,  insufficient  lime,  and  often  partly  due  to  too 
short  liming.  If  the  quantity  of  arsenic-lime  has  been  sufficient, 
it  thoroughly  cleanses  the  grain.  Particularly  evident  is  this 
difference  of  structure  of  grain  and  true  skin  manifested  by  the 
action  of  a  putrid  lime.  Here  we  can  readily  see  that  round, 
putrid  spots  varying  in  size  are  formed  on  the  flesh  side,  while 
the  grain  shows  no  symptoms  of  putrefaction  yet.  If  the  pro- 
cess of  putrefaction  be  at  this  moment  interrupted  by  addition 
of  fresh  lime,  for  instance,  the  resulting  leather  would  be  dam- 
aged inside,  while  the  grain  would  be  firm  and  sound.  As  a 
rule,  however,  such  putrefaction  in  the  lime  is  not  interrupted 
in  time,  because  if  a  tanner  is  so  ignorant  as  to  allow  his  limes 
to  become  putrid,  he  will  certainly  not  have  sufficient  sense 


DEPUTATION  OR  "  UNHAIRING." 


113 


to  notice  the  damage  to  his  stock  in  time  to  prevent  serious 
trouble. 

If  the  putrefaction  is  allowed  to  progress,  it  will  ultimately 
also  injure  the  grain,  which  will  become  manifest  by  the  glossy- 
looking  spot  which  can  be  punctured  by  thrusting  a  finger 
through  it  as  easily  as  through  glue  size.  We  recently  came  into 
a  beam-house  where  every  fifth  or  sixth  skin  was  so  damaged  by 
putrid  lime.  What  are  putrid  limes — perhaps  if  they  are  a  year 
old?  Yes,  certainly.  But  a  fresh  lime  can  certainly  not  be 
putrid.  That  depends.  If  the  fresh  lime  is  made  up  with  half 
of  the  old  putrid  lime  liquor,  as  is  often  done,  then  this  so-called 
"fresh  lime"  can  cause  putrid  spots  on  the  skins.  We  give 
these  facts  on  putrid  limes  simply  to  show  that  there  exists 
quite  a  difference  between  the  grain  and  the  hide  proper  in 
their  property  of  resisting  the  action  of  different  agents. 

It  will  pay  to  select  in  the  beam-house  such  skins  as  are 
wanted  for  fancy  colors,  and  to  work  them  out  well  on  the 
slating  table  before  tanning.  There  would  possibly  be  traces 
of  lime  fat  or  dirt  in  the  skins  if  not  properly  slated,  which 
would  cause  spotty  grain.  The  lime  forms  with  the  fat  a  lime 
soap,  insoluble  in  water,  which  can  be  removed  only  by  slating 
and  cannot  be  washed  out.  This,  remaining  in  the  skins,  would 
be  of  no  detriment  as  far  as  a  dull  or  kangaroo  finish  is  con- 
cerned, but  would  show  up  badly  in  glazing  or  fancy  colors. 

F.  E.  Atteaux  &  Co.,  Boston,  Mass.,  handle  sodium  sulphide 
in  large  quantities  and  would  send  full  directions  for  its  use  on 
all  kinds  of  hides  and  skins  on  application. 

DEPILATING  WITH  CHARCOAL. 

In  lieu  of  lime  for  removing  the  hair  and  cleansing  the  pores, 
charcoal,  which  is  very  cheap  in  parts  of  the  country  where 
wood  alcohol  is  made,  may  be  employed  cither  as  a  substi- 
tute for  lime,  or  the  hides  or  skins  may  be,  as  heretofore, 
first  partly  treated  with  lime  and  finally  treated  with  charcoal. 

The  carbonaceous  matter  employed  may  be  either  animal, 
vegetable  or  mineral  charcoal  in  suspension,  and  it  is  claimed 
8 


H4 


THE  MANUFACTURE  OF  LEATHER. 


by  William  Anderson,  of  Inverkeithing,  near  Edinburgh,  Scot- 
land, that  the  results  of  this  treatment  are  that  the  hairs  are 
loosened,  the  pores  of  the  skins  or  hides  purified,  and  the 
putrescent  matter,  grease  and  other  impurities  removed. 

Mr.  Anderson  states  that  the  most  advantageous  method  of 
carrying  this  invention  into  effect  is  as  follows :  The  hides  or 
skins  are  placed  in  water  of  6o°  F.,  with  powdered  wood  char- 
coal sufficient  to  give  it  the  consistence  of  cream,  the  hides  or 
skins  being  removed  and  then  placed  back  in  the  same  liquor 
each  day  until  the  hairs  are  sufficiently  loosened  to  yield  easily, 
care  being  observed  to  stir  the  charcoal  powder  which  may 
have  subsided  in  the  intervals  of  removal,  in  order  as  far  as 
possible  to  keep  it  in  suspension. 

The  hides  or  skins  are  afterward  washed,  fleshed  and 
scudded  as  in  the  ordinary  method,  when  they  are  ready  for 
tanning  without  other  treatment,  and  the  charcoal  powder  may 
from  time  to  time  be  revivified  by  drying  it  in  thin  layers  in 
the  sun  or  in  a  current  of  air. 

In  order  to  render  them  flat  and  soft,  and  to  remove  lime 
and  other  impurities  from  hides  or  skins  which  may  have  been 
treated  with  lime  for  the  purpose  of  removing  the  hairs,  the 
process  which  has  just  been  described  may  be  applied. 

DIPILATING  WI1H  SULPHIDE  OF  BARIUM. 

Foley  invented  the  following  process  for  treating  hides  and 
skins  previous  to  tanning,  and  it  relates  to  removing  the  hair 
and  epidermis  from  hides  and  skins  of  every  description,  and, 
however  cured,  softening  dried  and  cured  hides  and  skins,  and 
separating  the  wool  and  hair  from  skins  in  their  natural  state. 

For  unhairing  he  uses,  instead  of  lime,  but  in  a  somewhat 
similar  manner,  solutions  of  sulphide  of  barium  of  varying 
strengths,  prepared  by  dissolving  in  water  solid  sulphide  of 
barium,  produced  by  heating  fine  ground  sulphate  of  baryta 
mixed  with  carbonaceous  substances  to  about  a  white  heat  in 
a  reverberatory  furnace  or  other  suitable  appliance. 

In  treating  green  slaughter  hides  and  skins  to  remove  the 


DEPILATION  OR  "  UNHAIRING." 


hair  and  epidermis,  first  wash  them  to  remove  the  blood  and 
dirt,  and  then  immerse  them  in  a  strong  solution  of  sulphide  of 
barium,  about  150  Baume,  for  about  three  to  six  hours.  They 
are  then  withdrawn,  again  washed  and  taken  to  the  beam-house, 
to  be  treated  in  the  usnal  manner. 

In  the  treatment  of  salted  or  cured  hides  and  skins  for  the 
removal  of  the  hair  and  epidermis,  first  immerse  them  about 
ten  to  twelve  hours  in  an  old  or  partially  spent  solution  of  sul- 
phide of  barium,  for  the  purpose  of  cleansing  them  and  destroy- 
ing the  effect  of  the  salt  or  substance  with  which  they  were 
cured,  and  afterward  immerse  them  in  a  solution  of  sulphide  of 
barium  of  about  6°  to  8°  Baume  for  about  ten  hours,  when  they 
are  ready  for  the  usual  treatment  in  the  beam-house. 

In  the  treatment  of  dried  or  flint  hides  and  skins  it  is  neces- 
sary, before  the  hair  and  epidermis  can  be  removed,  to  soften 
them;  this  is  done  by  soaking  them  about  twenty-four  hours  in 
a  solution  of  sulphide  of  barium  that  has  already  been  used  for 
unhairing,  or  in  a  weak  solution  of  about  30  Baume. 

After  the  dried  hides  and  skins  are  thoroughly  softened  in 
all  their  parts,  in  the  manner  above  set  forth,  immerse  them,  for 
the  purpose  of  removing  the  hair,  and  epidermis,  in  a  solution 
of  sulphide  of  barium  of  about  50  Baume  for  about  six  hours, 
and  then  pass  them  on  to  the  beam-work. 

In  the  treatment  of  skins  for  the  removal  of  wool  and  hair, 
apply  on  the  flesh  side  of  the  skins,  by  any  suitable  means,  a 
concentrated  solution  of  sulphide  of  barium  mixed  with  any 
inert  substance,  to  the  consistency  of  thin  paste.  The  solution 
applied  in  this  manner  penetrates  the  skin,  loosens  the  roots  of 
the  wool  or  hair,  and  allows  it  to  be  removed  uninjured  and  in 
its  natural  condition. 

This  invention  has  advantages  over  the  liming  process  now 
in  use  for  removing  hair  from  hides  and  skins  and  softening 
them,  and  among  others  the  following  are  claimed  by  the  inven- 
tor: No  part  of  the  gelatinous  tissue,  grain,  or  substance  of 
the  hide  is  removed  or  disturbed  ;  hides  and  skins  are  left  in 
their  natural  state  and  suppleness  ;  at  least  twenty-five  per  cent. 


THE  MANUFACTURE  OF  LEATHER. 


greater  weight  of  leather  can  be  obtained  from  hides  treated  by 
this  invention  than  by  the  old  process  of  liming.  The  hair,  it 
is  claimed,  is  removed  in  one-twentieth  part  of  the  time  usually 
employed,  thus  effecting  a  great  saving  in  time,  labor  and  ex- 
pense. Hides  and  skins  treated  by  this  invention,  and  intended 
for  upper  leather,  do  not  require  to  go  through  the  operation  of 
"  bating,"  which  effects  another  saving  in  time  and  expense. 

WORKING-OUT  AND  UNHAIRING  ALL  KINDS  OF  HIDES  AND  SKINS  WITHOUT 
LIMES,  BATE,  DRENCH  OR  BEAMING. 

This  is  the  Peirson-Moor  process,  which  has  been  carefully 
and  thoroughly  tested  and  developed  during  the  past  three 
years  by  the  North  Star  Tannage  Co.,  manufacturers  of  glazed 
kid  and  other  leathers,  Philadelphia,  who  will  doubtless  testify 
to  its  value  and  economy. 

It  is  claimed  for  this  process  that  the  unhairing  can  be  done 
in  twenty-four  hours  at  about  one-half  the  present  cost,  with- 
out risk  or  damage  to  the  hide  or  skin. 

Stone,  Timlow  &  Co.,  Warren  St.,  New  York,  control  the 
patent,  which  is  dated  February  18,  1896. 

There  are  many  other  substances  which  have  been  used  for 
depilating,  which  need  not  here  be  mentioned. 

CHEMISTRY  OF  DEPILATORIES.* 

A  sample  of  liquor  from  an  old,  well-plunged  lime  pit  in  a 
tanyard  was  found  after  filtration  through  sand  to  have  a  specific 
gravity  of  1.0046  at  17. 50  C,  and  showed  a  feeble  reaction  for 
albumin.  The  total  nitrogen  was  determined  in  100  Cc.  by 
the  Kjeldahl  method,  and  the  difference  between  this  value  and 
the  nitrogen  found  in  the  total  solid  residue  was  regarded  as  the 
nitrogen  in  the  volatile  bases.  To  avoid  destruction  of  nitrogen- 
ous matter  during  evaporation,  sodium  bicarbonate  was  added 
in  quantity  sufficient  to  carbonate  the  lime  in  the  liquor.  The 
albuminoids  were  precipitated  by  feebly  acidifying  with  acetic 


By  J.  Von  Schroeder  and  W.  Schmidt-Dumont,  in  Dingler's  Polytechnic  Journal. 


DEPILATION  OR  "  UNHAIRING." 


117 


acid  and  warming.  Volatile  acids  were  distilled  in  steam  after 
acidifying  the  liquor  with  sulphuric  acid.  Estimation  of  caustic 
lime  proved  difficult  on  account  of  the  organic  matter  present. 
Analysis  of  the  sediment  which  settled  from  the  liquor  before  it 
was  filtered  gave  the  following  figures:  CaC03,  8.22;  CaO, 
43.99;  CaO  combined  with  organic  matter,  8.82;  and  organic 
matter,  38.97  per  cent. 

Since  this  contained  so  much  free  lime  it  was  concluded  that 
the  liquor  was  saturated  with  free  lime,  in  which  case  it  would 
contain  1.299  grms.  per  litre  at  1 50  C.  When  shaken  with 
lime,  however,  the  filtered  liquor  dissolved  a  considerable  quan- 
tity, showing  that  lime  had  been  lost  during  the  filtration 
through  sand. 

The  following  table  gives  the  results  of  the  analysis : 

Grms.  per  Litre. 


Organic  solid  matter   11.856 

Inorganic  matter   3. 158 

Containing  CaO*   2.010 

"        MgO   0.013 

"        alkali  sulphates  and  chlorides   1.130 

Total  nitrogen   '-649 

Comprising  N  in  solid  residues   1 .527 

"         N  in  volatile  bases   0.122 

Total  precipitate  by  acetic  acid   2.022 

Comprising  fatty  acids   0.044 

"        ash   0.002 

"        albuminoids  (14.21  per  cent.  N)   1.97° 

Nitrogen  in  filtrate  from  acetic  acid  precipitate   '-376 

Volatile  acids  (as  acetic  acid)   0.480 

Organic  matter  not  precipitated  by  acetic  acid  (containing 

13.41  per  cent.  N)   9-354 

*After  having  been  shaken  wiih  lime  the  liquor  contained: 

Grms.  per  Litre. 

Free  CaO   1-299 

Combined  CaO   1.678 

Total   2.977 


The  volatile  bases  present  had  the  odor  of  trimethylamin* 
and  the  volatile  acids  that  of  caproic  acid.  The  authors  do  not 
think  that  they  have  sufficient  evidence  to  enable  them  to  pro- 
nounce upon  the  nature  of  the  albuminous  organic  matter. 


THE  MANUFACTURE  OF  LEATHER. 


Experiments  here  described  in  which  lime  and  sodium  sul- 
phide were  together  dissolved  in  water  led  to  the  conclusion 
that  each  of  these  two  compounds  retains  its  individuality 
when  in  solution  in  the  presence  of  the  other ;  hence  it  may  be 
deduced  that  the  simultaneous  application  of  lime  and  sodium 
sulphide  for  unhairing,  whether  in  the  form  of  a  solution  or  of 
a  paste,  is  beneficial,  because  each  exerts  its  specific  action  on 
hide  and  hair,  not  because  there  is  a  formation  of  caustic  soda 
by  double  decomposition,  as  has  been  supposed.  The  lime 
probably  also  serves  to  protect  the  sodium  sulphide  from  de- 
composition by  any  carbon  dioxide  which  may  be  absorbed. 

For  the  proximate  analysis  of  red  arsenic,  the  authors 
recommend  that  the  arsenious  oxide  should  be  extracted  from 
20  grms.  of  the  sample  by  digestion  at  a  gentle  heat  with  200 
c.  c.  of  hydrochloric  acid  (5  per  cent.)  for  5  hours.  The  solu- 
tion may  then  be  oxidized  by  nitric  acid  and  evaporated  to  dry- 
ness, the  residue  being  heated  at  4000  C.  for  45  minutes  and 
weighed  as  arsenic  anhydride.  To  separate  As2S3  from  As,,S,, 
10  grms.  of  the  portion  from  which  the  As,0.t  has  been  ex- 
tracted may  be  shaken  at  the  ordinary  temperature  with  200 
c.  c.  of  ammonia  (2  per  cent.)  until  no  more  arsenic  is  dis- 
solved ;  an  aliquot  portion  of  the  solution  is  evaporated  to  dry- 
ness and  the  As^Sa  weighed.  A  sample  of  red  arsenic  thus 
examined  gave  :  As/S3,  73.56  per  cent. ;  As^S*,  26.1 1  per  cent. ; 
As20:),  0.37  per  cent. 

To  investigate  the  part  played  by  red  arsenic  in  the  mixture 
of  it  with  lime  which  is  commonly  used  as  a  depilatory,  40 
grms.  of  lime  and  8  grms.  of  red  arsenic  were  made  into  a  thin 
magma  with  160  c.  c.  of  water,  this  magma  was  heated  on  the 
water  bath  for  one  hour,  then  made  up  to  a  volume  of  3150 
c.  c.  with  water,  filtered,  and  the  solution  analyzed.  It  was 
found  that  4.13  per  cent,  of  the  arsenic,  93.50  per  cent,  of  the 
sulphur,  and  15.25  per  cent,  of  the  lime  remained  in  solution. 
The  undissolved  residue  was  brown  from  the  presence  of  tin- 
combined  arsenic,  so  that  the  chief  reactions  may  be  repre- 
sented by  the  equations  : 


DEPUTATION  OR  "  UNHAIRING." 


I  19 


( 1 )  3  ASjS, + 9CaO  +  3H,0  =  2Ca3C  As03)  2  +  3Ca ( S  H )  „+ As2 
( 2 )  2  As.2S:t + 9CaO  +  3H,0  ^  2Ca3  ( AsO:)) ,+ 3Ca(SH), 

There  is,  however,  the  dissolved  arsenic  to  be  accounted  for, 
since  calcium  arsenite  was  found  to  be  quite  insoluble  even  in 
presence  of  excess  of  lime.  Experiments  showed  that  calcium 
arsenite  reacts  with  a  solution  of  calcium  hydrosulphide,  with 
formation  of  calcium  thioarsenite  which  passes  into  solution. 
Supposing  the  arsenic  to  exist  in  this  form  in  the  unhairing 
liquor,  it  may  be  calculated  from  the  foregoing  figures  that  one 
litre  of  the  liquor  contains  4  355  grms.  of  Ca>(AsS:,)2,  27.780 
grms.  of  Ca(SH)2  and  1.299  grms.  of  CaO.  It  appears  then 
that  the  sole  constituents  of  the  lime  and  red  arsenic  depilatory, 
which  can  be  considered  as  active,  are  the  calcium  hydrosul- 
phide and  the  small  proportion  of  calcium  thioarsenite,  unless, 
indeed,  ammonia  and  amines  developed  during  the  sojourn  of 
the  hide  in  the  mixture  can  dissolve  any  of  the  calcium 
arsenite.  This  point  was  settled  in  the  negative  by  the  analysis 
of  a  liquor  which  had  been  used  for  three  weeks  for  treating 
kips,  when  it  was  found  to  contain  somewhat  less  arsenic  than 
it  did  originally,  showing  that  the  amines  and  ammonia  which 
were  undoubtedly  present  had  not  rendered  the  arsenic  com- 
pounds more  soluble.  The  putrid  odor  of  this  arsenical  lime 
liquor  seems  to  contradict  the  common  statement  that  the  func- 
tion of  the  arsenic  is  that  of  an  antiseptic. 

It  remained  to  ascertain  whether  the  calcium  thioarsenite 
possesses  any  depilatory  properties.  For  this  purpose  arsen- 
ious  sulphide  was  dissolved  in  calcium  hydrosulphide  solution. 
In  this  solution,  containing  CaS.As2S.i,  pieces  of  raw  hide  were 
immersed  and  kept  in  stoppered  vessels  for  about  a  month  ; 
none  of  the  pieces  were  materially  altered  except  that  each  was 
colored  yellow  throughout ;  the  hair  was  as  firm  as  before  im- 
mersion, and  the  hide  as  soft  and  elastic.  When  exposed  to 
the  air  the  pieces  lost  their  yellow  color,  consequent  on  the 
decomposition  of  the  thioarsenite,  and  at  the  same  time  the 
hair  was  loosened.  The  same  effect  was  observed  in  the  case 
of  pieces  of  hide  left  in  the  thioarsenite  solution  in  open  ves- 


120 


THE  MANUFACTURE  OF  LEATHER. 


sels.  There  was  depilatory  action,  but  it  was  found  to  be  due 
to  calcium  hydrosulphide,  for  the  arsenic  had  all  separated  as 
sulphide  and  the  solution  contained  Ca(SH)2. 

The  authors  conclude  that  the  activity  of  arsenical  limes  is 
due  to  calcium  hydrosulphide  and  calcium  hydroxide  alone. 

DEPUTATION  BY  SWEATING. 

Villon  claims  to  have  traced  the  loosening  of  the  hair  in  the 
sweating  process  to  the  putrefactive  action  of  a  specific  bacte- 
rium which  he  styles  the  bacterie pilline.  This  organism  is  aero- 
bic and  feeds  upon  the  hair  substance  (pilline),  converting  it 
into  leucine,  tyrosine,  butyric  acid,  margaric  acid,  and  ammo- 
nia;  the  ammonia  dissolves  the  coriin  and  thus  swells  the  hide. 
Villon  further  claims  he  has  obtained  pure  cultures  of  this  bac- 
terium on  ammoniacal  gelatin — ammonia  having  an  inhibitory 
effect  upon  other  bacteria — and  to  have  inoculated  sterilized 
hide  therewith,  when  an  evolution  of  ammonia  and  loosening  of 
the  hair  followed. 

The  experiments  on  which  Villon  bases  his  conclusions  have 
been  criticised  on  the  ground  that  the  method  adopted  for  ob- 
taining antiseptic  conditions  was  not  sufficiently  drastic.  Ster- 
ilization of  hide  by  exposure  to  a  temperature  of  500  C.for  24 
hours,  followed  by  ten  minutes  at  1 10°  C.  (the  method  adopted 
by  Villon),  was  found  to  be  impossible.  Recourse  was  there- 
fore had  to  the  use  of  antiseptics,  and  carbon  bisulphide  in  the 
form  of  potassium  ethyl  dithiocarbonate  (potassium  xanthoge- 
nate),  was  employed  as  being  easily  removed  by  washing,  and 
not  deleterious  to  the  hide. 

The  following  conclusions  are  drawn:  A  dilute  solution 
(1 — 0.25  per  cent.),  of  potassium  xanthogenate  will  gradually 
kill  all  micro-organisms  existing  in  hide  from  which  the  hair 
has  not  been  removed,  without  changing  the  hide  to  a  percep- 
tible extent,  even  after  half  a  year's  immersion.  A  short  expo- 
sure (24-48  hours)  to  this  antiseptic  will  prevent  general  putre- 
faction, but  will  not  destroy  a  streptococcus  which  by  decom- 
posing the  rctc  malpighii,  loosens  the  hair.    The  organisms 


DEPILATION  OR  "UNHAIRIMi." 


121 


which  remain  active  in  this  way  evolve  ammonia  without  any 
marked  quantity  of  other  odoriferous  compounds,  and  are  ap- 
parently killed,  before  there  has  been  any  attack  on  the  hide 
fibre,  by  the  decomposition  products  of  the  rete  malpighii  cells. 
The  identity  of  these  micro-organisms  with  a  known  form  re- 
mains to  be  proved :  so  far,  a  tendency  of  the  colonies  to 
develop  in  the  form  of  an  intricate  and  extensive  network  seems 
to  characterize  this  streptococcus. 

It  is  proposed  that,  in  the  very  probable  event  of  the  pure 
culture  of  the  bacterium  which  is  responsible  for  the  loosening 
of  the  hair  in  the  sweating  process  being  obtained,  a  rational 
system  of  sterilizing  the  hide  by  carbon  bisulphide  vapor  and 
then  inoculating  it  with  the  necessary  bacterium  shall  be  fol- 
lowed by  the  tanner  who  unhairs  by  sweating. 

In  the  preliminary  preparation  of  sole  leather  we  use  the 
"  cold-sweat  "  process,  while  in  Great  Britain  and  other  portions 
of  Europe,  the  warm-sweat  method  is  employed  ;  but  for  the 
production  of  upper  leather,  the  hides  are  limed  about  as  we  do. 

Dry  flint  hides  are  the  ones  that  are  usually  prepared  in  this 
country  by  the  employment  of  the  sweating  process  for  depi- 
lating, and  it  is  highly  essential  that  the  hides  should  be  prop- 
erly soaked,  and  all  their  parts  be  thoroughly  softened  before 
they  are  subjected  to  the  sweating  process,  for  if  not  intelligently 
prepared,  they  harden  in  spots,  forming  "  old  grain." 

"  Frieze"  is  principally  caused  during  the  process  of  sweat- 
ing when  the  grain  of  the  hide  is  inclined  to  be  tender  and  has 
the  appearance  of  being  scraped  off.  "  Black  spots"  or  "  old 
grain  "  are  blotches  of  dark  color,  and  when  the  hide  is  tanned, 
rolled  hard,  and  finished  these  spots  cannot  be  buffed  off,  and 
sometimes  they  extend  over  the  whole  side  of  leather,  as  has 
been  stated  in  the  chapter  treating  of  the  soaking  and  softening 
of  hides. 

A  BUILDING  FOR  SWEATING  HIDES  OR  SKINS. 

The  arrangement  shown  in  Figs.  18,  19,  and  20  for  sweating 
hides  and  skins,  is  the  invention  of  Mr.  William  M.  Mason,  of 


122 


THE  MANUFACTURE  OF  LEATHER. 


Buffalo,  N.  Y.,  and  the  valuable  points  which  it  contains  will  be 
readily  appreciated  by  tanners  who  employ  the  process  of 
sweating. 

Fig.  1 8  is  a  sectional  elevation  of  a  building  embodying  the 
improvements.  Fig.  19  is  a  horizontal  section  in  line  x  x. 
Fig.  20  is  a  vertical  section  at  right  angles  to  Fig.  19. 

Fig.  18. 


This  invention  consists  of  a  vault  or  apartment  having  a  ven- 
tilator provided  with  a  regulating  valve,  and  a  water-floor  con- 
sisting of  a  series  of  communicating-troughs,  arranged  and 
operating  as  hereafter  described,  for  the  purpose  of  softening 
dry  hides  and  sweating  the  same. 

In  the  drawings,  A  represents  a  building  of  any  kind,  and  B 
is  a  ventilator  at  the  top.  If  the  whole  building  is  used  as  the 
vault,  the  ventilator  simply  extends  from  the  top,  as  in  black 


DEPILATION  OR  "  UNHAIRING." 


123 


lines,  Fig.  18,  but,  if  only  one  story  is  used,  the  ventilator  is 
extended  below  and  passed  through  the  flooring,  as  shown  by 
the  dotted  lines,  thereby  leaving  the  upper  story  or  stories  free 
for  other  uses.    A  valve,  a,  is  preferably  hung  in  the  ventilator 


Fig.  19. 


at  any  point,  and  provided  with  cords  b  b,  by  which  it  is  ope- 
rated. The  use  of  the  valve  is  to  graduate  the  escape  of  the  cur- 
rent from  the  interior,  by  closing  more  or  less  of  the  ventilator 
space.    Any  desired  number  of  the  ventilators  may  be  used, 


Fk;.  20. 


A 

k  CI, 


^\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\^ 


and  they  may  be  extended  to  any  desired  height,  the  latter 
being  preferable  as  it  produces  an  active  ventilation.  A 
water-floor,  C,  is  employed,  to  which  is  applied  water  to  pro- 
duce the  evaporation.  The  inventor  prefers  the  form  shown, 
which  consists  of  a  series  of  troughs  or  water-ways,  c  c  c,  open 
at  alternate  ends,  as  shown  at  d  d,  so  as  to  form  a  zigzag  water 


124 


THE  MANUFACTURE  OF  LEATHER. 


communication  around,  as  indicated  by  the  arrows  in  Fig.  19. 
The  water  enters  by  an  induction-pipe,  f,  at  one  end,  and 
escapes  by  the  eduction-pipe,  f,  at  the  other  end.  This  cur- 
rent or  flow  of  the  water  is  essential  to  discharge  such  gases  as 
are  absorbed  by  the  water  and  keep  the  water  pure.  Either 
fresh  or  salt  water  may  be  employed ;  but  the  latter  is  prefer- 
able, especially  in  hot  weather,  as  it  produces  a  colder  atmos- 
phere, and  the  salt  acts  as  a  preservative  to  the  hides  in  sweat- 
ing. A  different  arrangement  of  the  water-floor  and  its  troughs 
may  be  used,  and  the  throwing  or  spraying  of  the  water  on  the 
floor  might  be  used  with  a  similar  effect,  g  g  g are  the  slats 
or  poles  for  hanging  the  hides,  h  li  Ji  are  slats  laid  as  a  floor- 
ing over  the  water-troughs,  with  interstices  left  between  to  allow 
of  the  evaporation. 

By  the  means  above  described,  there  is  produced  cold  sweat- 
ing in  contradistinction  to  the  warm  sweating  heretofore  prac- 
tised. By  so  doing,  it  is  claimed  that  the  requisite  dampness 
is  always  obtained  without  any  danger  of  heating  and  spoiling 
the  hides.  The  ammonia  and  gases  are  all  carried  off  as  fast 
as  they  are  generated,  thus  removing  at  once  the  great  cause 
of  putrefaction.  There  is,  consequently,  no  loss  of  the  hides 
from  this  source,  and  but  little  care  or  time  is  necessary  in 
conducting  the  operation,  as  compared  with  the  usual  method. 

Any  arrangement  of  doors,  windows,  or  other  apertures  or 
entrances  may  be  used,  and  the  vault  may  be  so  arranged  that 
an  opening  may  be  made  in  the  same  at  the  bottom  at  any 
time,  for  the  purpose  of  admitting  air  to  assist  the  ventilating 
action  when  the  atmosphere  is  heavy,  as  is  sometimes  the  case. 

CARE  TO  BE  OBSERVED  IN  SWEATING  HIDES. 

Some  tanners  prefer  to  maintain  the  temperature  for  the 
sweating  pits  at  from  6o°  to  Jo°  F. ;  but  the  risk  increases 
largely  in  proportion  to  the  increase  of  temperature. 

Faithful  attention  should  be  paid  to  the  hides  during  the 
advanced  stage  of  sweating,  and  when  any  give  indications  of 
advancing  too  rapidly  they  should  be  removed  to  the  bottom  of 
the  pit  and  properly  cared  for. 


DEPILATION  OR  "  UNHAIRING." 


125 


When  the  sweating  process  is  used  for  small  hides  or  kips, 
they  should  be  thoroughly  washed  in  very  clean  water,  spread 
out  after  four  days'  soaking,  well  rinsed  and  drained,  then  laid 
together  in  packs  in  such  a  manner  that  the  hair  is  outward, 
and  the  pairs  of  skins  back  to  back.  Hang  them  over  the  poles 
of  the  sweating  pit,  with  the  tail  end  upon  the  one  side,  and  the 
head  on  the  other.  Then  close  the  door  and  stop  it  up  well  so 
that  the  air  may  be  excluded  as  much  as  possible,  and  leave 
matters  thus  until  the  odor  of  the  sweating  process  becomes 
quite  strong,  which  is  an  indication  that  the  process  of  depi- 
lation  is  about  to  begin,  and  from  this  time  out  the  greatest 
attention  should  be  paid  to  the  stock. 

The  working  of  the  sweating  process  is  shown  by  a  sharp  lye 
which  forms  under  the  hair,  and  which  drops  off  the  instant 
fermentation  sets  in. 

Light  hides  should  not  be  placed  in  too  strong  lime  ;  these 
hides  should  rather  be  operated  upon  by  degrees  and  always 
with  weak  lime,  after  coming  from  the  sweating  vault. 

The  sweating  process  regulates  and  hastens  the  expansion  of 
the  hide,  opens  the  pores,  and  places  the  hide  in  a  state  similar 
to  that  in  which  it  was  at  the  time  the  animal  was  slaughtered. 
To  prepare  it  for  the  leather  dressing  process,  it  will  be  found 
enough  to  work  the  hide  lightly  on  the  flesh  side  with  the  iron, 
when  it  is  taken  out  of  the  sweating  vat,  so  as  to  stretch  out 
the  wrinkles  that  may  appear  before  the  hide  is  placed  in  the 
lime-pit,  which,  as  has  been  said,  should  always  first  contain  a 
weakened  lime-bath. 

With  regard  to  the  large  hides,  such  as  those  imported  from 
South  America  and  elsewhere,  we  urgently  recommend  that 
they  should  be  subjected  to  the  sweating  process,  for,  we  repeat 
it,  the  sweating  system  has  not  only  the  effect  of  facilitating 
the  process  of  depilation,  but  of  giving  to  dry  wild  hides  that 
development  of  which  they  stand  in  need. 

Buenos  Ayres  hides  are  a  species  of  hide  which  softens  easily 
and  in  a  regular  manner.  It  is  admitted  that  hides  which  are 
allowed  to  remain  continuously  in  water  soften  less  readily  than 


126 


THE  MANUFACTURE  OF  LEATHER. 


those  which  are  alternately  soaked  and  piled.  And  now  let  us 
consider  how  piling  compares  with  sweating.  Piling  is  nothing 
more  nor  less  than  a  slow  inward  sweating,  and  while  it  is  slow 
you  run  the  risk  of  having  the  edges  damaged,  by  giving  the 
time  necessary  to  effect  a  good  result.  So  in  order  to  save  the 
back  and  extremities  you  are  obliged  to  dispense  with  a  com- 
plete softening  of  the  hide,  and  moreover  lose  time,  which  is 
always  the  result  of  irregular  soak  r;  .  We  seek  to  attain  in 
soaking  the  hide  the  raising  up  of  the  fibres,  in  order  to  save 
those  parts  of  the  hide  which  were  wet,  and  became  dried  dur- 
ing transportation  ;  and  the  best  mode  of  doing  this  consists  in 
accelerating  the  operation,  so  as  to  obtain  a  thorough  soaking 
by  the  sacrifice  of  from  seven  to  eight  days. 

Stagnant  water  does  not  give  the  dry  hide  time  to  become 
completely  softened  again,  at  least  it  injures  the  grain,  which 
becomes  lost  before  the  water  has  had  time  to  penetrate  the 
fibres  of  the  hide. 

Under  these  circumstances,  sweating  is  alone  of  use,  and  if 
necessary,  a  softening  during  twenty-four  hours  in  open  water 
will  be  sufficient  to  secure  a  satisfactory  result,  as  experiment 
has  proven. 

Soak  the  hides  in  water  for  twenty-four  hours,  mark  the  flesh 
side  well,  and  rinse  the  hair  side  thoroughly,  so  as  to  rid  it  of 
all  foreign  substances,  so  that  no  faulty  spots  may  ensue;  let 
them  drain  in  a  heap  during  four  or  five  hours,  and  bring  them 
to  the  sweating  process  as  above  described.  Sprinkle  them 
with  fresh  water  from  a  gardener's  watering  pot,  provided  with 
a  sieve-like  spout,  and  after  the  hides  have  been  again  allowed 
to  drain  off",  put  them  back  in  the  sweating  vat. 

Three  sprinklings  with  the  watering-pot  will  be  found  ample, 
in  combination  with  the  sweating  process,  to  soften  the  driest 
and  oldest  hides  to  such  a  degree  that,  even  if  they  are  of  the 
heaviest,  they  can  at  once  be  divested  of  the  hair.  Then 
separate  them  after  rinsing,  lay  them  again  in  water,  clean  and 
scrape  them,  and  do  not  interrupt  the  gradual  course  which 
the  hide  has  to  undergo. 


DEPILATION  OR  "UNHAIRING." 


127 


What  we  have  last  above  stated  should  only  be  resorted  to 
when  suitable  water  is  wanting  for  proper  soaking,  for  wc 
recommend  above  all  things  that  the  hide  be  carefully  soaked 
in  water,  as  this  raises  it  well ;  but  in  all  cases,  whichever  mode 
of  soaking  be  followed,  the  hides  should  never,  as  a  general 
rule,  be  allowed  to  stay  in  the  water  longer  than  four  days,  or 
from  five  to  six  days  in  severely  cold  weather.  Of  course  the 
sprinkling  with  a  watering-pot  is  then  superfluous,  and  there 
will  then  only  remain  the  placing  of  the  hides  in  the  sweating 
vat  to  be  attended  to.  They  should  be  left  in  it  from  four  to 
six  days,  according  to  the  season  of  the  year. 

The  operation  of  the  sweating  process  is  decomposition, 
which  causes  the  grain  to  lose  its  elasticity,  or  holding  power 
over  the  hair,  so  that  it  may  slip  off  almost  involuntarily,  leav- 
ing the  pelt  so  soft  and  flabby  that  even  the  advocates  for  this 
method  recommend  a  lime-bath  after,  to  resuscitate  the  pelt, 
or  what  they  call  raise  it,  previous  to  putting  in  to  tan. 

THE  WARM  SWEATING  PROCESS. 

The  process  of  warm  sweating  largely  employed  in  Germany 
and  many  other  portions  of  Europe  is  usually  conducted  in  a 
buried  box  of  suitable  size,  from  which  the  air  is  rigidly  excluded. 
The  box  has  racks  firmly  attached  to  the  sides,  opposite  each 
other,  and  into  which  stout  notched  poles  are  fitted  to  receive 
the  hides  after  they  are  properly  rolled.  The  cover  of  the  box 
is  usually  composed  of  loose  boards,  which  are  convenient  for 
handling  in  filling  or  emptying  the  sweat-box. 

After  removal  from  the  water  and  draining  off  for  a  few 
hours,  the  hides  are  placed,  hair  side  out,  alongside  the  sweat- 
box,  and  the  sides  folded  in  towards  the  back,  or  the  hides  are 
rolled  together  from  the  side  towards  the  back. 

If  the  sweat-box  is  of  sufficient  depth,  folding  in  of  the  head 
is  not  necessary,  but  otherwise  it  has  to  be  done  to  prevent  the 
hide  from  touching  the  bottom  of  the  box.  To  keep  the  head 
from  sliding  out,  which  might  easily  happen,  both  ends  of  the 
rolled  hide  are  securely  tied  with  twine.    After  covering  the 


128 


THE  MANUFACTURE  OF  LEATHER. 


bottom  of  the  box  with  a  layer  of  spent  tan  three  or  four  inches 
thick,  the  hides  are  hung  close  together  over  the  above-men- 
tioned poles.  The  box  is  then  tightly  covered  with  boards 
upon  which,  to  prevent  all  access  of  air,  tan  is  piled  to  the 
depth  of  about  ten  or  twelve  inches,  and  well  trodden  down. 
Warm  steam  is  frequently  used  in  order  to  accelerate  the  sweat- 
ing process.  Though  this  method  offers  some  advantages,  great 
risk  is  connected  with  it,  and  the  utmost  care  must  be  exercised 
to  guard  against  overheating.  Spontaneous  heat,  which  is  gen- 
erally developed  in  five  to  six  days,  is  always  preferable,  as  it 
acts  more  uniformly  than  heat  produced  by  steam. 

After  remaining  in  the  sweat-box  for  a  few  days,  the  con- 
dition of  the  hides  is  examined  by  removing  the  tan  from 
one  corner  and  pushing  a  board  far  enough  back  to  allow  the 
introduction  of  the  hand.  If  after  examining  several  hides,  it 
is  found  that  no  heat  has  been  developed,  and  the  hair  not 
loosened,  the  box  is  immediately  closed.  With  some  experi- 
ence and  skill  it  is  an  easy  matter  to  determine  how  long  the 
hides  will  still  have  to  remain  in  the  box;  fourteen  days  being 
frequently  required  before  the  hair  becomes  loose.  The  great- 
est care  and  precaution  are  necessary  during  the  entire  sweat- 
ing process,  as  putrefaction  promoted  by  heat  makes  rapid 
progress,  and  may  cause  great  loss. 

SWEATING  FRESH  HIDES. 

After  cutting  out  the  horns,  fresh  ox  hides  intended  for  sole 
leather  are  spread  out  and  thoroughly  salted  upon  the  flesh 
side.  After  folding  each  hide  in  the  middle  from  head  to  tail, 
and  tucking  in  the  shanks,  sides,  and  head,  it  is  formed  into  a 
pack ;  several  of  these  packs  are  then  piled  upon  one  another, 
and  covered  with  woolen  covers  or  straw.  It  is  best  to  perform 
these  operations  in  a  cellar. 

It  is  advisable  to  use  three  pounds  of  salt  for  a  large  hide,  as 
this  quantity  is  required  to  protect  the  flesh  side  against  putre- 
faction, and  besides  makes  the  hides  more  solid.  After  twelve 
to  sixteen  hours  the  hides  are  turned.    The  packs  are  taken 


DEPILATION  OR  "  UNHA1RING." 


129 


apart,  the  hides  refolded,  and  again  piled  up  and  covered,  after 
which  they  require  turning  only  every  three  or  four  days.  By 
this  method  the  hair  becomes  loose  in  two  to  three  weeks. 

Fresh  salted  hides  are  generally  not  subjected  to  the  sweat- 
ing process,  it  being  preferred  to  place  them,  after  thorough 
soaking  in  water,  in  weak  lime,  when  the  hair  becomes  suffi- 
ciently loose  in  from  six  to  eight  days  to  allow  of  the  hides 
being  unhaired. 
9 


CHAPTER  VIII. 


UNHAIRING  AND  FLESHING  BY  HAND  AND  MACHINERY. 

In  the  United  States  the  unhairing  and  fleshing  of  hides  is 
done  by  both  machinery  and  hand  ;  but  the  hand  method  is 
passing  away,  and  it  will  soon  be  used  only  by  the  small  country 
tanners. 

The  operations  are  conducted  in  the  "  beam-house,"  an  in- 
terior view  of  which  showing  the  forms  of  beams  employed  and 
other  details  of  the  hand  method  is  given  in  Fig.  21 ;  the 
German  form  of  beam  and  stand,  used  in  tawing  establishments 
for  skins  is  shown  in  Fig.  22,  and  the  unhairing  knife  in 
Fig.  23. 

After  loosening  the  hair,  the  hides,  if  they  have  been  sub- 
jected to  the  sweating  process,  are  removed  from  the  sweating 
vaults,  drawn  through  fresh  water,  and  allowed  to  drain.  This 
operation  prevents  drying,  promotes  cooling  off,  and  interrupts 
putrefaction,  and  as  hides  thus  treated  will  usually  keep  for  two 
days  without  suffering  damage,  unhairing  need  not  be  hurried. 

Limed  stock  is  taken  from  the  "  limes  "  directly  to  the  un- 
hairing beams  or  to  the  unhairing  machines,  and  is  not  passed 
through  water  as  in  the  case  of  hides  that  have  been  subjected 
to  the  sweating  process. 

The  "unhairing"  of  hides  and  skins  by  the  hand  method  is 
usually  effected  by  placing  them  upon  a  beam  and  scraping  the 
hair  off  with  a  concave  blade  called  the  "  unhairing  knife," 
which  agrees  with  the  curvature  of  the  beam,  and  the  operation 
is  performed  by  men  of  great  physical  strength,  endurance  and 
skill,  acquired  only  by  long  and  continued  application  ;  but 
this  manner  is  too  slow  to  meet  the  large  and  constantly  in- 
creasing demand  for  leather,  and  consequently  aids  in  render- 

(  130  ) 


132 


THE  MANUFACTURE  OF  LEATHER. 


ing  this  material  too  dear  for  a  commodity  of  such  varied  and 
indispensable  employments,  and  in  order  to  facilitate  unhairing 
a  large  number  of  machines  have  been  invented  in  this  country  ; 
but  of  this  we  shall  have  more  to  say  later  on. 


Fig.  22. 


To  offer  increased  resistance  to  the  tool  in  the  hand  process 
of  unhairing,  very  fine  sand,  or  road  dust,  mixed  with  a  small 
quantity  of  ashes,  is  sometimes  rubbed  into  the  places  where 
the  hair  is  difficult  to  remove ;  but  this  practice  is  injurious  to 
the  grain  and  should  not  be  employed. 

As  depilation  is  more  easily  accomplished  by  pushing  the 
knife  against  the  hair,  the  sides  from  the  hind  shank  towards 
the  head  are  first  operated  upon  and  then  towards  the  back. 

Fresh  hides  are  operated  upon  as  soon  as  the  hair  can  be 
pulled  out  around  the  shanks,  and  from  the  upper  part  of  the 
head. 

After  depilation  by  hand  the  hides  are  again  placed  in  water, 
and  rinsed  and  left  to  remain  over  night,  after  which  they  are 
usually  ready  for  fleshing. 

In  the  process  of  unhairing  hides  and  skins,  sometimes  some 


UNHAIRING  AND  FLESHING. 


133 


of  them  are  cut  or  so  injured  that  they  are  reduced  from  the 
first  quality  to  a  lower  grade,  and  thus  loss  is  occasioned.  It  is 
well  known  also  that  after  the  hair  has  been  removed  by  the 
usual  process  of  liming  and  scraping  or  rubbing  it  off",  there 
remains  a  short  fine  hair  or  fur,  and  also  hair  on  the  edges  and 
extremities  of  the  hide,  which  has  to  be  removed  generally 
during  the  scouring  by  a  sharp  knife  or  other  instrument  called 
the  "  short-hair  knife."  The  chief  mischief  is  done  to  the  hides 
in  removing  the  fine  hair  by  cutting  or  clipping  the  grain  of 
the  hide,  and  when  this  is  too  frequently  done  a  guard  should 
be  attached  to  the  knife  in  order  to  prevent  the  possibility  of 
damaging  the  skin,  especially  when  it  is  intended  for  delicate 
work. 

The  knife  is  made  of  steel,  like  ordinary  knives,  with  the 
usual  handle,  but  for  convenience  the  blade  may  be  made  with 
a  double  edge,  the  under  side  of  which  is  somewhat  convex, 
being  thickest  in  the  middle  and  gradually  decreasing  in  thick- 
ness to  the  edge.  The  upper  side  of  the  blade  may  have  a 
dovetail  rib  in  the  middle  or  thick  part  of  the  blade,  and  from 
this  rib  to  the  edge  on  either  side  the  blade  should  be  some- 
what concave. 

The  guard  is  made  with  a  dovetail  groove,  so  as  to  slip  closely 
on  to  the  rib.  It  is  made  of  German  silver,  brass,  copper,  or 
any  suitable  metal  or  material,  and  should  project  beyond  the 
edge  of  the  blade  about  the  sixteenth  part  of  an  inch.  Its  edges 
should  be  thick  enough,  or  slightly  corrugated  on  the  inner 
side,  so  as  to  give  it  requisite  stiffness. 

When  the  knife  needs  sharpening  the  guard  may  be  easily 
slipped  off  and  also  ground  down  if  necessary. 

The  concave  side  of  the  blade  and  the  openings  of  the  guard 
allow  the  hair  to  pass  off  without  inconvenience. 

The  knife  is  used  in  the  same  way  as  the  ordinary  knife,  and 
is  of  great  value  in  cleaning  kid-skins  and  other  varieties  of 
skins  used  for  glove  leather,  where  so  much  care  has  to  be 
exercised  to  prevent  clipping  the  grain. 

In  France  particular  attention  is  paid  to  the  beam  work  on 


134 


THE  MANUFACTURE  OF  LEATHER. 


calf  skins,  and  we  will  describe  the  process  of  unhairing  and 
fleshing  as  practised  in  that  country. 

The  beam-house  is  so  arranged  as  to  avoid  loss  of  time  for  the 
workmen  in  taking  out  of  the  vats  and  putting  back  the  skins 
they  are  working. 

They  have  at  least  three  vats  for  five  or  six  beam-hands ; 
these  vats  have  a  capacity  of  375  or  400  gallons  each;  the 
water  runs  into  and  out  of  them  with  rapidity  so  as  to  fill  and 
empty  them  promptly. 

The  unhairing  beams  are  five  feet  long,  and  are  covered  with 
strong  sheet  zinc,  and  thus  have  a  smooth  surface  convenient 
for  the  work  of  the  operator,  and  which  avoids  breaks  and  knife 
cuts  on  the  grain  side. 

The  sheet  of  zinc  is  3  ft.  4  in.  long  and  2  ft.  1  in.  wide ;  the 
beam  presents  a  convex  line  of  7^  inches  rise.  The  zinc  is 
fastened  with  round-headed  tacks  well  nailed  down,  and  must 
be  put  about  1^  inches  below  the  head,  for  the  following 
reasons :  It  often  happens  that  it  is  necessary  to  put  for  drip- 
ping 35  or  30  skins  on  the  same  beam,  and  to  leave  them  on  it 
for  several  hours,  in  which  case  the  undermost  hide  which  rests 
on  the  edge  of  the  head  of  the  beam  will  have  a  deep  curved 
mark  pressed  on  the  neck,  and  this  mark  cannot  be  taken  out  in 
tanning  or  even  in  currying.  The  grain  at  that  spot  looks  like 
parchment,  and  refuses  to  take  the  tannin.  A  prominent  French 
tanner  tried  to  discover  the  origin  of  these  spots,  and  found 
fhat  they  had  been  caused  by  the  sharp  edge  of  the  beam-head, 
and  he  put  the  zinc  about  i1/^  inches  further  down,  and  from 
that  time  he  did  not  find  any  more  of  these  creases,  which  had 
previously  spoiled  the  skins  and  diminished  their  value. 

The  beam  for  fleshing  the  skins  and  for  thinning  the  neck  is 
broader,  and  less  arched  than  the  other;  it  is  lens  shaped. 
This  facilitates  the  work  of  the  knife,  for  by  having  a  broader 
surface,  the  edge  is  less  liable  to  slip  and  make  flaws,  and  the 
work  progresses  more  rapidly,  as  the  operator  is  not  forced  to 
change  the  position  of  his  calf-skin  so  often,  and  when  he  reduces 
a  throat  or  a  head,  he  does  so  in  a  more  uniform  manner. 


UNHAIRING  AND  FLESHING. 


135 


To  unhair  slaughtered  calf-skins  fresh  from  the  Paris  market, 
the  workman  lays  two  large  skins  at  a  time  on  the  beam,  and 
when  of  medium  size  places  three ;  but  when  the  calf-skins  are 
small,  places  four.  In  order  to  avoid  scratches  and  to  make  the 
action  of  the  knife  easier,  the  workman  gives  great  care  to  the 
edge,  and  leaves  no  trace  of  hair  upon  the  skins.  He  then 
places  them  in  water,  and  rinses  them. 

Next  a  skillful  workman  cuts  the  navels  and  nipples,  trims 
the  rumps,  fashions  the  breeches  and  the  tails,  going  entirely 
around  the  skins,  and  reaches  the  neck,  which  requires  special 
treatment.  Should  there  be  any  flesh  left  by  the  butcher  on  the 
flanks  and  necks,  it  is  lightly  removed  with  the  fleshing  knife. 

FLESHING  BY  THE  HAND  METHOD. 

This  operation,  which  consists  in  removing  all  fleshy  and 
fatty  matter  by  means  of  a  sharp  blade,  requires  great  skill.  In 
some  tanneries  the  work  is  performed  with  a  fleshing  knife  hav- 
ing a  curved  blade,  which  measures  about  seventeen  and  a  half 


Fig.  24. 


inches  between  the  handles  for  the  kind  used  for  hides,  and 
about  sixteen  and  a  half  inches  for  skins  ;  this  form  of  flesher  is 
shown  in  Fig.  24. 

A  workman  once  accustomed  to  handling  this  tool  can  turn 
out  very  clean  work,  but  it  is  far  better  to  use  for  this  purpose 


Fig.  25. 


the  so-called  German  fleshing  knife,  which  has  a  blade  measur- 
ing from  twenty  to  twenty-three  inches  between  the  handles, 


136 


THE  MANUFACTURE  OF  LEATHER. 


and  about  an  inch  and  three-quarters  wide,  and  which  is  shown 
in  Fig.  25. 

The  German,  or  spring  fleshers,  are  especially  recommended 
for  extra  clean  work ;  they  make  a  more  satisfactory  cut  than 
the  other  styles  of  fleshers,  as  the  workman  is  able  to  readily 
adjust  it  to  the  curved  shape  of  the  beam,  which  is  a  great 
advantage,  over  the  stiff  straight-edged  flesher  cutting  on  an 
oval  or  convex  surface. 

The  spring  pating  fleshers  measure  about  seveteen  inches 
between  the  handles. 

In  the  commencement  of  fleshing  a  hide  is  laid  escutcheon 
part  down  over  the  beam,  and  shaved  the  entire  width  of  the 
beam,  and  as  far  down  as  the  workman  can  reach,  this  hide, 
forming  a  support  which  is  later  on  replaced  by  one  entirely 
shaved.  The  hide  to  be  fleshed  next  is  laid,  head  down,  over 
the  beam,  and  after  shaving  it,  first  the  entire  width  of  the 
beam,  and  next  the  sides,  it  is  turned  over  and  finished  by 
shaving  the  escutcheon.  In  fleshing  the  left  hand  precedes  the 
right,  and,  to  prevent  injury  to  the  hide  by  cutting  into  it,  the 


Fig.  26. 


workman  should  accustom  himself  to  drive  the  knife  without 
stopping,  as  far  as  he  can  reach  from  the  top  to  the  bottom 
of  the  beam. 

The  projecting  filaments  or  shreds,  and  those  parts  of  the 
borders  of  the  skin  which  are  thicker  than  the  rest,  are  cut  off 
with  a  sharp  knife  and  the  portions  thus  removed  are  sold  to 
the  glue  manufacturer. 

For  the  removal  of  butcher  cuts  not  accomplished  by  flesh- 
ing, the  smoothing  stone  often  proves  a  great  advantage. 

The  saw-toothed  flesher  sometimes  employed  for  dry  hides 
is  shown  in  Fig.  26. 


UNHAIRING  AND  FLESHING. 


137 


The  turning  steels  employed  are  round  and  three  square, 
sometimes  the  latter  style  is  file  cut  on  one  side.  The  three 
square  turning  steel  is  shown  in  Fig.  27. 

In  the  portion  of  this  chapter  devoted  to  the  unhairing  of 
calf-skins,  the  manner  of  cutting  the  navels  and  nipples,  and 
trimming  the  rumps,  etc.,  of  calf-skins  was  described.  Follow- 
fng  this  operation  the   flesh  sides  are  gone  over  with  the 


Fig.  27. 


"  worker,"  the  skins  being  pushed  crosswise  or  diagonally, 
starting  from  the  humps  of  the  shoulder.  Large  calf-skins  are 
put  on  the  beam  one  at  a  time ;  but  two  skins  are  put  at  once 
on  the  beam  if  they  are  of  medium  size  or  thin. 

In  order  to  have  this  work  done  successfully  the  workman 
must,  by  means  of  short  and  brisk  blows,  applied  in  a  kind  of 
mowing  fashion,  get  off  by  main  strength  all  the  fleshy  and 
parchment-like  tissues,  from  the  body  of  the  hide  and  from  the 
sinews  of  the  fore  and  hind  legs. 

The  action  must  be  brisk  and  vigorous  on  the  crupper,  where 
the  nerve  of  the  hide  must  be  entirely  broken  ;  go  over  lightly 
on  the  fore  and  hind  flanks  without  even  trying  to  take  off"  the 
tissues  with  which  they  are  covered  ;  the  collar  must  also  be 
managed  carefully ;  the  action  must  be  brisk  on  the  necks  and 
heads  if  there  are  any  tissues. 

In  acting  in  this  way  the  nerves  of  the  hides  are  completely 
broken  on  their  sinewy  parts,  and  due  consideration  is  given  to 
the  weak  or  hollow  spots. 

This  work  is  very  important,  and  must  be  overlooked  with 
great  care,  as  the  skins  that  are  not  worked  in  the  way  just 
explained,  but  which  are  merely  and  indiscriminately  scraped 
for  flesh,  never  develop  themselves  well  in  tanning,  refusing 
to  absorb  the  tannin  and  give  poor  results  in  the  currying. 

When  all  the  skins  have  undergone  this  process  they  are  put 
to  soak  for  six  hours  in  a  vat  of  clear  water. 


138  THE  MANUFACTURE  OF  LEATHER. 

Then  they  are  next  counter-fleshed,  putting  two  hides  at 
once  on  the  beam ;  they  are  again  soaked  in  water  for  an  hour 
or  two  ;  they  are  takan  up  and  gone  over  with  the  "  worker," 
putting  two  large  skins  on  the  beam,  or  more  if  they  are  small; 
the  flesh  side  to  be  upwards.  It  is  very  important  to  have  this 
operation  well  done  with  the  "  worker,"  slight  blows  at  first, 
then  heavier,  in  order  to  empty  and  purify  them  of  lime ;  then 
the  grain  is  cleaned  with  a  knife  of  which  the  bevel  must  be 
very  smooth  in  order  to  avoid  scratches. 

After  these  two  operations  the  hides  are  put  to  soak  in  clean 
water  for  three  or  four  hours.  They  are  then  taken  in  hand 
again  and  given  a  last  working  of  the  grain  071  the  body  of  the 
hides  only ;  are  rinsed  for  the  last  time,  and  piled  awaiting 
storage  in  the  vats. 

It  requires  a  sure  hand  to  do  the  fleshing  of  a  calf-skin. 
The  work  must  be  done  in  mowing  fashion  only,  as  straight 
heavy  blows  are  apt  to  enter  the  skin  and  leave  marks  of  cuts. 
The  butchers  do  generally  enough  mischief  to  the  skins  with- 
out the  tanners  adding  any  more.  It  requires  then  some  know- 
ledge and  experience  to  avoid  all  mishaps;  and  furthermore 
the  tanner's  is  a  rough  trade  and  it  requires  a  pair  of  stout, 
hard  and  vigorous  arms  to  make  a  good  beam-hand. 

SOAKING  HIDES  AFTER  FLESHING  BY  THE  HAND  METHOD. 

This  operation  exerts  a  great  influence  upon  the  quality  of 
the  leather,  and  is  much  more  highly  esteemed  in  Germany  and 
France  than  in  this  country. 

After  fleshing,  the  hides  are  placed  in  water  as  clean  and 
clear  as  possible,  and  if  running  water  is  used,  a  location  where 
there  is  but  little  current,  or  none  whatever,  is  chosen.  If  a 
river  or  creek  has  to  be  used  for  the  purpose,  a  pole  is  driven 
perpendicularly  in  the  bottom  of  the  river,  upon  which  the 
hides  are  successively  strung  through  the  ear  hole  and  pushed 
towards  the  bottom,  care  being  observed  to  keep  them  spread 
out  horizontally.  If  the  water  is  deep  enough  as  many  as 
twenty  hides  may  be  suspended  one  above  the  other.    To  give 


UNHAIRING  AND  FLESHING. 


139 


a  better  support  to  the  pole  the  end  projecting  above  the  water 
is  pushed  through  a  strap  secured  to  the  bank  of  the  river. 

The  hides  are  drawn  up  twice  daily  by  means  of  a  hook, 
rinsed  off,  moved  and  replaced  in  the  manner  described. 

SOAKING  HIDES  IN  A  STEEPING  CISTERN  AFTER  FLESHING. 

In  tanneries  located  on  a  river  or  connected  with  a  water 
conduit,  provision  is  generally  made  in  Germany  and  France 
for  steeping  cisterns,  which  are  of  great  advantage  for  the 
preparation  of  sole  and  upper  leathers.  They  are  constructed 
either  of  stone  or  wood  and  so  arranged  that  the  water  can  be 
admitted  and  drawn  off  very  rapidly  at  will. 

After  fleshing,  the  hides  are  placed  in  the  steeping  cistern 
previously  filled  with  fresh  water.  After  12  hours  they  are 
moved,  the  water  is  drawn  off,  and  the  hides,  after  the  admit- 
tance of  fresh  water,  are  replaced  in  the  steeping  cistern.  This 
operation  should  be  scrupulously  repeated  twice  daily  to  pre- 
vent putrid  soaking  from  making  its  appearance  to  the  injury 
of  the  hides.  By  putrid  soaking,  which  is  recognized  by  a  foul 
odor  of  the  water,  we  understand  the  assumption  of  a  flabby 
condition  by  the  hides,  while  on  the  other  hand,  with  a  fresh 
and  sound  soaking,  they  feel  firm  to  the  touch  and  smooth 
upon  the  grain  side,  and  the  water  has  no  odor  whatever. 

HOW  LONG  SHOULD  THE  HIDES  SOAK  AFTER  FLESHING,  AND  WHAT 
INDICATES  THEIR  READINESS  FOR  SCOURING? 

In  this  country  the  hides,  after  fleshing,  are  soaked  for  a  much 
shorter  period  than  in  Germany  and  France.  Hides  intended 
for  sole  leather,  with  us,  are  generally  allowed  to  soak  over 
night,  while  in  the  countries  which  have  been  named,  the  time 
for  soaking  is  from  three  to  five  days,  the  period  depending 
much  on  the  temperature  of  the  water,  the  hides  meanwhile 
being  frequently  examined  as  regards  their  readiness  for  scour- 
ing. They  are  ready,  1st,  when  the  fine  film  still  adhering  on 
places  after  fleshing  can  be  readily  detached  by  scraping  with 
the  finger  nail,  and  2d,  when  by  pressing  with  the  fingers  upon 


140 


THE  MANUFACTURE  OF  LEATHER. 


the  grain  side  the  indented  places  remain  visible.  As  these  in- 
dications can  be  most  readily  perceived  after  rinsing,  it  is  well 
to  make  these  tests  after  each  rinsing  operation. 

Hides  intended  for  the  production  of  upper  leather  after 
being  "  green  shaved  "  are  placed  directly  in  a  bate  of  hen 
manure  and  worked  sufficiently  with  a  drench  wheel,  after 
which  for  about  5  minutes  they  are  worked  in  a  wash-wheel, 
and  are  then  worked  over  with  a  hide-working  machine  and 
are  next  placed  in  spring  water  to  soak  over  night.  It  is  con- 
ceded that  the  bate  neutralizes  the  lime  in  the  hide  and  leaves 
this  class  of  leather  more  pliable  than  when  it  is  subjected  to 
long  soaking  in  water,  which  while  it  will  extract  the  lime 
imparts  an  undesirable  harshness  to  upper  leather. 

FLESHING  AND  UNH AIRING  BY  MACHINERY. 

The  processes  of  unhairing  and  fleshing  hides  as  usually  per- 
formed are  the  most  laborious  operations  in  the  business  of  tan- 
ning and  require  the  workman  to  be  constantly  in  contact  with 
cold,  wet  hides,  which  is  very  injurious  to  the  constitution, 
subjecting  most  operators  to  disease  and  forcing  many  to  leave 
the  business.  The  fleshing  and  unhairing  of  hides  and  skins  is 
now  successfully  performed  by  machinery  at  a  cost  of  less  than 
one-third  of  the  hand  method. 

After  the  hides  have  been  soaked  they  are  fleshed  before  they 
are  limed,  when  machinery  is  employed,  and  after  the  liming 
they  are  unhaired,  and  then  refleshed  to  take  off  the  flesh 
"  puffed  up,"  or  raised  by  liming,  or  left  on  after  first  fleshing. 
For  sole  and  rough  leather  the  process  is  the  same.  A  few 
tanners  "  green  shave,"  or  flesh  out  of  the  lime,  and  do  not 
flesh  out  of  the  water  soak  at  all. 

In  Fig.  28  is  shown  the  Vaughn  new  heavy  construction 
beam-house  machine  for  fleshing  from  the  soaks,  unhairing,  re- 
fleshing  from  the  limes,  green  shaving,  and  working  out,  or  fine 
hairing,  and  largely  used  by  tanners  of  sole,  harness,  belting, 
rough,  upper  or  grains,  buff",  colors,  wax,  kips  or  calf. 

It  will  do  all  these  operations  perfectly  and  completely,  and 


142 


THE  MANUFACTURE  OF  LEATHER. 


the  manufacturers  guarantee  its  work  to  be  far  superior  in  every 
respect  to  that  done  by  hand  or  any  other  machine.  They  will 
send  them  out  on  trial  to  any  responsible  concern,  and  if  the 
results  do  not  substantiate  the  above  statement,  it  to  be  no  sale. 

Remember,  the  builders  fit  each  machine  for  the  work  it  is 
sent  out  to  do,  thereby  insuring  to  every  tanner  perfect  results 
on  his  own  particular  class  of  stock,  in  his  own  particular  way 
of  working  it.  This  their  long  experience  in  all  kinds  of  tan- 
neries enables  them  to  do  to  perfection.  It  is  beyond  dispute 
that  what  would  be  good  work  and  good  results  on  one  kind  of 
stock,  would  be  ruinous  on  another. 

The  principle  and  construction  is  the  best  that  could  possibly 
have  been  conceived  for  the  purpose.  This  fact  is  conceded  by 
all.  The  machine  and  work  being  at  all  times  under  the  per- 
fect control  and  observation  of  the  operator,  who  sees  the  hide 
being  worked  as  the  bed  carries  it  through  the  under  cylinder, 
and  then  just  how  it  has  been  done  as  the  bed  returns  to  its 
place  again,  thus  each  and  every  hide  being  worked  properly 
and  perfectly,  and  if  the  desired  result  is  not  obtained  by  once 
passing  through,  it  is  readily  seen  by  the  operator,  who,  by 
simply  moving  the  lever,  causes  it  to  be  worked  as  many  times 
as  desired  without  handling  the  hide  or  taking  much  extra 
time.  This  is  important,  and  it  is  claimed  can  be  done  by  no 
other  make  or  style  of  machine. 

The  cylinders  also  are  a  great  and  important  factor  in  the 
success  of  this  machine,  and  the  splendid  work  and  results  they 
give  cannot  be  obtained  with  any  other  style  or  form,  as  has 
been  proved  by  their  years  of  service,  and  the  many  attempts 
to  equal  them.  By  their  peculiar  construction,  the  hide  is 
worked  both  in  length  and  width  atone  and  the  same  time,  and 
the  hide,  lying  as  it  does  on  the  drum  or  bed,  covered  with  a 
soft  rubber  cushion,  is  subject  to  no  strain  or  damage  whatever 
on  the  body,  head,  flanks  or  shanks. 

The  adoption  and  sole  use  of  this  machine  in  all  the  leading 
tanneries  of  the  country,  is  proof  positive  of  its  superiority  over 
hand  work,  or  that  of  any  other  machine. 


144 


THE  MANUFACTURE  OF  LEATHER. 


One  machine  is  fitted  to  do  the  whole  beam-house  work  if 
desired,  so  can  be  used  to  great  profit  and  advantage  by  those 
running  small  tanneries. 

But  one  operator  required. 

Economy  of  space  and  power. 

Both  quantity  and  quality  of  work  obtained. 

Will  work  equally  well  whole  hides,  sides,  kips  and  calf. 

Sizes  or  length  of  cylinders  54  inches,  72  inches,  84  inches, 
108  inches. 

This  machine  is  built  by  the  Vaughn  Machine  Company, 
Peabody,  Mass. 

The  cylinders  used  with  this  machine  are  shown  in  Figs.  29 
and  30. 

The  success  of  machinery  for  working  hides,  skins  or  leather 
depends  on  the  cylinders  used,  and  it  will  at  once  be  seen  by 
these  cuts  why  the  Vaughn  machines  are  so  superior  to  hand 
work,  as  by  their  novel  construction  the  blades  are  working 
the  stock  both  lengthways  and  sideways  at  the  same  time. 

The  builders  vary  the  form  and  material  of  them  according 
to  the  work  required  for  them  to  do. 

Fig.  31  shows  a  grinding  lathe  or  cylinder  and  roll  sharpen- 
ing and  turning  up  machine,  made  by  the  Vaughn  Machine 
Company,  Peabody,  Mass. 

As  will  be  seen  by  the  cut,  this  machine  works  much  like  an 
ordinary  lathe,  excepting  the  cylinder  runs  in  bearings  the 
same  as  when  at  work  in  the  machine  (instead  of  on  centres  as 
would  be  the  case  in  using  an  ordinary  lathe),  therefore  it  is 
bound  to  be  kept  perfectly  true  for  the  work  in  the  machine  in 
which  it  is  used. 

The  builders  use  this  machine  for  sharpening  the  cylinders 
of  their  machines  where  the  emery  dust  or  grit  of  the  automatic 
grinder  on  the  machine  would  be  a  detriment  or  cause  damage 
to  the  stock,  as  by  using  this  all  the  above  is  kept  entirely  away 
from  the  machine  and  stock  being  worked. 

It  is  a  valuable  machine  to  have  where  Belt  Knife  Splitting 
Machines  are  used,  as  it  will  keep  the  rubber  rolls  perfectly 
true  and  in  fine  condition. 


146  THE  MANUFACTURE  OF  LEATHER. 


UNHAIRING  MACHINES. 

Fig.  32. 


Whitney's  "  jumbo  "  unhairing  machine. 


Fig.  32  illustrates  Whitney's  patent  double-acting  unhairing 
and  hide-working  machine.  It  is  made  in  four  sizes:  52 
inches,  64  inches,  82  inches,  and  109  inches. 

This  machine  (familiarly  called  "Jumbo,")  differs  from  the 
original  well-known  Whitney  Unhairing  Machine  in  this  respect : 
it  is  made  to  feed  the  hide  both  ways,  unhairing  it  when  it  is 
feeding  into  the  machine,  and  working  it  when  it  is  feeding  out, 
thus  effectually  cleaning  it  (especially  the  shanks  and  end 
pieces)  at  one  operation.  As  no  part  of  the  hide  jumps  through 
the  machine,  no  part  escapes  a  thorough  working. 

In  operating  the  machine  the  hide  is  laid  upon  a  traveling  rub- 
ber apron  which  carries  it  to  the  "  bite  "  between  the  two  upper 
feed  rolls,  and  the  apron  supported  by  the  lower  feed  roll, 


UNHAIRING  AND  FLESHING. 


147 


thence  to  the  work  roll  filled  with  slate  blades  housed  at  back 
of  machine  which  revolves  against  the  hide  at  a  high  rate  of 
speed,  thus  thoroughly  cleansing  it.  After  the  hide  has  passed 
half  way  through  the  machine,  the  operator  reverses  the  feed 
and  the  hide  is  fed  outwardly  into  his  hands,  when  he  turns  it 
and  works  the  other  half  in  the  same  way  as  first  half. 

It  is  obvious  that  particular  hides  may  be  worked  over  sev- 
eral times,  or  they  may  be  fed  right  through  as  in  the  old-style 
unhairing  machine,  and  may  be  left  at  either  front  or  back  of 
machine  when  sufficiently  worked. 

The  shipping  mechanism  is  very  simple  and  works  without 
noise  or  jar.  It  consists  of  two  loose  belts  running  in  opposite 
directions,  which,  when  alternately  tightened,  drive  the  feed 
gearing.  Either  belt  is  tightened  by  throwing  the  weighted 
lever  attached  to  the  swinging  binder  frame  to  one  side  or  the 
other  off  its  centre  of  gravity,  thfc  working  belt  being  made 
sufficiently  tight  by  adjusting  the  ball  weights  so  as  to  just  throw 
it  over  the  centre. 

The  belts  are  made  double  and  endless,  and  should  be  each 
57  inches  long.  If  they  stretch  from  use  they  can  be  adjusted 
by  lowering  the  frame  to  which  the  binder  pulley  shafts  are 
attached. 

This  machine  will  unhair  and  work  out  75  to  100  sides  per 
hour.  It  is  in  use  in  many  tanneries.  It  takes  but  a  small 
amount  of  power.  The  slate  roll  is  so  constructed  that  it  will 
not  cut  or  scratch  the  hide  in  the  least,  and  the  slates  can  be 
quickly  replaced.  They  are  the  best  quality  and  not  easily 
broken.  Steel  bladed  work  rolls  are  furnished  with  the  ma- 
chine in  place  of  slate  when  so  ordered. 

This  machine  is  made  by  the  Whitney  Machine  Co.,  Win- 
chester, Mass. 

The  machine  shown  in  Fig.  33  is  particularly  adapted  for  use 
in  small  tanneries.  It  is  really  three  machines  in  one.  It  will 
both  flesh,  unhair  and  work  out  250  sides  per  day.  It  can  be 
adjusted  to  do  different  kinds  of  work  by  simply  taking  out 
the  fleshing  roll,  and  substituting  an  unhairing  or  a  working- 


148  THE  MANUFACTURE  OF  LEATHER. 

out  roll,  which  operation  takes  but  a  few  moments.  It  is  per- 
fectly noiseless  in  its  work. 

When  used  for  fleshing,  this  combined  machine  fleshes  the 
hide   in  the  same  manner  as  the  regular  fleshing  machine. 

Whitney's  patent  combined  unhairing  fleshing  and  working-out 

MACHINE. 

Fig.  33. 


In  quantity  and  quality  of  work  both  machines  are  equal.  For 
economy  in  the  use  of  power  and  simplicity  of  operation,  there 
is  no  better  fleshing  machine  in  the  market  than  the  Whitney 
machine.    It  has  been  adopted  by  many  leading  tanners. 


UNH AIRING  AND  FLESHING.  1 49 

| 

For  unhairing,  this  machine  can  be  altered  so  as  to  feed  a 
hide  over  a  table  into  the  machine  from  one  end  to  the  other 
without  reversing  it,  the  same  as  hides  are  fed  into  the  regular 
unhairing  machine. 

For  "  working  out,"  the  combined  machine  is  unexcelled.  It 
can  be  furnished  with  either  of  the  various  kinds  of  •steel  or  slate 
working  out  rolls,  as  may  be  best  adapted  to  the  special  kind  of 
leather  to  be  produced.  Special  Slating  Rolls  are  made  to  order 
by  the  Whitney  Machine  Co.,  Winchester,  Mass. 

Whitney's  patent  ke-fleshing  machine. 


Fig.  34. 


150  THE  MANUFACTURE  OF  LEATHER. 

f 

The  machine  shown  in  Fig.  34  is  made  in  four  sizes:  52 
inch,  64  inch,  90  inch  and  109  inch,  and  it  is  designed  to  re- 
flesh,  or  "  cut  over,"  the  hide  after  it  has  been  limed  or  unhaired 
and  once  fleshed  out  of  the  water  soak.  This  operation  takes 
off  the  flesh  "puffed  up"  by  liming  or  left  on  after  the  first 
fleshing.  As  the  hide  is  in  a  slippery  state,  it  spreads  very 
easily,  and  there  is  no  danger  of  cutting  it.  The  feed  rolls  are 
so  constructed  as  not  to  injure  the  hide  in  the  least,  and  yet  are 
so  powerfully  arranged  as  to  hold  and  feed  the  hide  without  the 
aid  of  clamps  of  any  kind. 

The  operation  of  re-fleshing  saves  the  tan-liquor,  which 
otherwise  would  be  wasted  tanning  refuse.  Without  cutting 
into  the  hide  in  the  least,  it  leaves  it  so  clean  as  to  save  the 
operation  of  skiving  and  the  expense  of  maintaining  a  skiving 
machine.  After  re-fleshing,  the  hide  will  more  quickly  take  the 
tan  liquor,  and  a  heavier  split  can  be  obtained. 

The  capacity  of  this  machine  is  from  800  to  1000  sides  per 
day  of  heavy  hides,  or  from  1400  to  1800  skins.  It  is  easily 
operated  by  an  ordinary  beam-house  workman. 

In  operation,  a  hide  is  thrown  into  the  machine  over  the  two 
front  feed  rolls  (see  cut)  which  are  in  a  state  of  rest.  Foot 
pressure  on  the  treadle  swings  the  two  feed  rolls,  with  the  hide 
upon  them,  up  against  the  cutter  roll,  and  also  binds  the  hide 
over  a  middle  feed  roll  housed  in  the  frame  of  the  machine. 
Just  as  the  hide  comes  in  contact  with  the  cutter  roll,  the  feed 
rolls  commence  to  revolve  outwardly  and  pull  the  hide  against 
the  cutter  roll  and  into  the  operator's  hands.  After  the  first 
half  of  the  hide  is  re- fleshed,  the  second  half  is  cleaned  in  the 
same  manner. 

This  machine  is  noisless  in  operation,  simple  and  substantial 
in  construction.  It  takes  from  three  to  four  horse-power  to 
drive  it.  The  cutting  cylinder  blades  are  made  of  the  best 
hardened  steel,  and  are  sharpened  by  a  patent  grinder  attached 
to  the  machine. 

This  machine  is  built  by  the  Whitney  Machine  Co.,  Win- 
chester, Mass. 


UNHAIRING  AND  FLESHING. 


The  craft  of  the  tanner  is  one  which  dates  from  time  imme- 
morial, but  of  recent  years  great  strides  have  been  made  in  the 
advancement  of  the  art.  New  ideas  have  come  to  the  front, 
and  better  leather  is  now  being  made  and  at  a  lower  cost  of 
production  than  ever  before.  At  present,  more  attention  and 
thought  are  being  devoted  to  this  department  of  the  trade; 
competition  and  the  demand  for  a  better  and  greater  variety 
of  leather  has  made  it  necessary. 

The  tanners  of  the  past  have  been  proverbially  unprogressive, 
and  it  is  now  only  in  the  face  of  severe  competition  and  dimin- 
ishing profits  that  they  are  waking  up  and  asking,  "  What  can 
we  do  to  be  saved?"  The  answer  is  to  economize  in  every 
way  that  it  is  possible  to  practice  economy. 

The  tanner  of  to-day  must  be  alert  and  constantly  on  the 
lookout  for  new  and  improved  processes  and  machines  and 
adopt  them  when  found,  for  it  is  only  in  this  way  that  he  can 
keep  abreast  of  the  times  and  make  a  profit. 

There  are  tanners  who  still  unhair  and  flesh  by  hand  because 
the  machines  they  tried  years  ago  for  these  purposes  were 
crude  and  unsatisfactory,  and  they  forget  that  the  modern 
machines  are  not  only  successful  but  decidedly  economical 
in  use. 

It  has  been  demonstrated  that  the  unhairing  and  fleshing 
machines  are  now  a  practical  success,  and  in  many  tanneries 
the  beam  men  have  disappeared,  the  machines  having  taken 
their  places,  saving  to  the  manufacturer  fully  two-thirds  of  the 
cost  of  unhairing  and  fleshing. 

Small  tanners  have  an  idea  that  they  can  not  afford  to  buy 
beam-house  machinery — this  is  a  mistake,  as  one  machine  of 
small  size  can  be  purchased  which  will  not  only  unhair  but 
flesh,  work-out,  re-flesh  or  "  cut  over,"  and  do  a  great  many 
other  desired  things  by  simply  changing  the  roll. 

Tanners  in  small  country  yards  will  not  long  continue  to 
unhair  with  the  knife  over  the  beam — this  is  not  always  thor- 
oughly done,  particularly  in  dressing  leather  which  has  to  go 
through  bates.    Men  say,  "Oh,  it  will  come  out  in  scudding;" 


152 


THE  MANUFACTURE  OF  LEATHER. 


but  we  would  say,  unhair  them  clean,  and  most  of  the  scud  will 
leave  the  skin  in  the  first  stage,  it  will  pure  better,  and  be  less 
flabby  in  the  offal,  and  for  sole  leather  it  will  be  better  color, 
and  better  quality.  This  should  be  a  great  consideration,  but 
it  is  much  overlooked.  We  regret  to  know  the  practice  is  to 
get  over  the  work,  not  how  well  it  may  be  done. 

Unhairing  by  machinery  is  a  great  acquisition,  and  much 
more  dependence  can  be  placed  upon  the  regularity  of  the 
work,  and  less  danger  of  the  grain  being  injured  by  cuts  and 
scratches.  A  great  writer  truly  said  English  and  American 
workmen  are  not  so  painstaking  as  Continental  workmen,  but 
every  part  of  manufacture  requires  this  painstaking,  or  perfec- 
tion will  not  be  attained  ;  neglect  in  any  one  stage  cannot  be 
compensated  in  the  following  ones.  For  instance,  if  a  part  of 
the  pelt  is  not  thoroughly  softened  in  the  soak,  the  depilator 
will  harden  it,  the  hair  will  be  difficult  to  remove,  and  the 
tannic  acids  will  not  penetrate  so  as  to  amalgamate  and  chem- 
ically unite — the  leather  will  be  hard  and  shelly. 

Unhairing  and  fleshing  by  machinery  seem  to  start  the  pelt 
right,  it  goes  through  the  tanning  process  right  and  comes  out 
right  in  the  finishing. 


CHAPTER  IX. 


BATING. 

THE  operation  of  immersing  hides  and  skins  intended  for  the 
manufacture  of  pliable  leathers,  in  an  alkaline  solution  consist- 
ing of  the  dung  of  chickens,  pigeons,  dogs,  or  in  bran  water,  or 
in  any  of  the  compounds  intended  to  supersede  the  dung  solu- 
tions, or  to  be  used  in  combination  with  them,  is  termed  either 
"bating,"  "abating,"  "  grainering,"  "  reducing,"  "  drenching," 
or  "  puring." 

The  greatest  risk  in  any  beam-house  is  that  of  bating,  mainly 
for  two  reasons,  either  that  of  over-bating  or  insufficient  bating. 

The  one  is  as  bad  as  the  other,  for  in  either  case  the  leather 
when  tanned  will  not  bring  full  prices.  Because  where  leather 
has  been  underbated,  the  stock  still  containing  lime  is  bound  to 
produce  hard,  brittle  and  cracky  leather,  and,  if  fancy  colors 
are  desired,  uneven  coloring  is  the  result.  No  stock  not  thor- 
oughly freed  from  lime  can  possibly  make  good  or  standard 
leather.  Now,  on  the  other  hand,  if  stock  is  overbated,  the 
result  is  loose-grained  and  spongy  leather,  which  also  com- 
mands a  poor  price. 

This  great  risk,  which  plays  so  important  a  part  in  every 
tannery,  is  recognized  by  all  tanners,  and  many  patent  bates 
have  been  sprung  upon  the  market  to  live  but  a  short  life,  for 
the  same  trouble  was  found  with  them  as  with  the  various 
manures  and  bran,  viz. :  that  beamsmen  could  never  control 
the  bate,  and  it  kept  them  in  a  constant  strain  of  mind  as  to 
whether  this  or  that  pack  would  come  out  right  or  not. 

It  does  not  seem,  strange,  therefore,  that  the  theory  and 
practice  of  the  beam-house  preparation  of  hides  and  skins 
should   have   remained  practically  unchanged  for  centuries. 

(  i53  ) 


154 


THE  MANUFACTURE  OF  LEATHER. 


While  chemistry  has  invaded  the  domain  of  so  many  other  in- 
dustries and  wrought  wonderful  and  beneficent  improvements, 
it  is  only  within  very  recent  years  that  the  tanner  has  been 
willing  to  concede  that  chemistry  had  anything  to  do  with  the 
art  of  leather  manufacture.  It  is,  nevertheless,  true  that  the 
whole  science  and  art  of  tanning  rests  upon  and  is  dependent 
upon  chemical  action  and  reaction.  For  this  reason  many  able 
chemists  have  within  recent  times  directed  their  attention  to  the 
scientific  investigation  of  the  processes  connected  with  the  tan- 
ner's art,  with  the  result  that  much  has  been  learned  regarding 
the  technology  of  these  processes,  and  the  tanner  has  been 
given  explanations  covering  the  "  why  and  wherefore  "  of  his 
methods,  which  should  be  invaluable  to  him  in  the  prosecution 
of  his  business.  It  is  a  melancholy  fact,  however,  that  the 
tanners  as  a  class  are  reluctant  to  countenance  new  ideas  and 
suggestions  which  run  counter  to  their  preconceived  notions, 
and  are  prone  to  cling  to  the  old  ways  and  to  belittle  the  efforts 
of  scientific  men,  who  would  help  them  to  a  better  understand- 
ing of  their  trade  and  would  give  them  valuable  aid  in  advanc- 
ing them  toward  improved  methods. 

It  is  a  standing  disgrace  to  leather  manufacturers  that  they 
have  for  so  long  a  time  adhered  to  the  practice  of  using  manure 
bates  for  the  purpose  of  removing  the  lime  from  hides  and 
skins  after  they  have  been  unhaired.  The  use  of  a  manure  bate 
is  not  only  an  extremely  disgusting  operation,  but  it  is  also  a 
highly  dangerous  proceeding,  for  the  hides  and  skins  are  more 
or  less  liable  to  injury  or  damage  from  the  moment  they  are 
placed  in  such  a  bate.  It  has  been  ascertained  and  proved 
beyond  a  doubt  that  the  action  of  a  manure  bate  is  due  to  an 
energetic  fermentation,  producing  innumerable  bacteria,  which 
eat  away,  deplete  and  dissolve  the  hide  substance,  and  if  skins 
are  left  long  enough  in  such  a  bate  they  will  entirely  disappear. 
This  fermentation  also  produces  several  of  the  weak  organic 
acids,  which  together  with  the  ammoniacal  salts  present  in  the 
manure,  combine  with  the  lime,  forming  soluble  lime  salts  that 
are  removed  from  the  skins  by  subsequent  washing  and  work- 


BATING. 


155 


ing  on  the  beam.  The  same  may  be  said  of  a  bran  bate;  the 
fermentation  of  the  bran  producing  acetic,  lactic,  butyric,  and 
similar  organic  acids,  which  form  soluble  salts  with  lime;  but 
these  same  acids  moreover  act  as  solvents  of  the  hide  tissue, 
and  the  result  is  the  formation  of  a  nidus  for  the  propagation  of 
myriads  of  bacteria  which  attack  the  gelatine  of  the  hide  sub- 
stance. If  the  operation  of  manure  bating  and  bran  drenching 
is  not  carefully  watched  and  properly  conducted,  serious  dam- 
age is  often  encountered  which  entails  irreparable  loss  to  the 
tanner ;  this  being  especially  true  where  skins  are  intended  to 
be  colored  and  finished  on  the  grain.  The  "  puer  run  "  grain  is 
well  known  to  tanners,  and  they  are  only  too  well  acquainted 
with  the  discouraging  losses  they  have  met  with  on  this  account. 

It  is  unnecessary  to  go  into  details  as  to  why  the  lime  or 
other  alkaline  depilatories  should  be  removed  from  hides  and 
skins  previously  to  tanning;  it  being  sufficient  to  say  that  it  is 
agreed  upon  all  sides  that  it  is  a  necessity  to  perform  this  ope- 
ration in  order  to  obtain  good  merchantable  leather.  Now  it 
is  plain  that  subjecting  skins  for  this  purpose  to  animal  putres- 
cent and  vegetable  fermenting  solutions  is  objectionable,  and  it 
is  equally  evident  that  a  working  substitute  that  would  do  away 
with  the  undesirable  features  of  these  solutions  would  be  a  ver- 
itable blessing  to  the  tanner.  There  have,  of  course,  been  many 
substitutes  proposed  and  many  patents  issued  to  inventors  cov- 
ering processes  for  bating,  but  they  have  all  been  more  or  less 
based  upon  the  idea  of  producing  a  ferment  that  would  act  upon 
the  skins  in  much  the  same  manner  as  the  old  processes.  The 
attempt  has  been  made  to  build  up  by  synthesis  a  substance 
that  would  contain  the  essential  elements  found  by  analysis  to 
be  contained  in  the  dog,  hen  and  pigeon  manure.  A  com- 
pound made  of  old  cheese,  sal-ammoniac  and  glucose  has  been 
used.  But  such  preparations  all  have  the  defects  inherent  in 
fermentive  processes.  From  a  purely  chemical  standpoint  a 
dilute  solution  of  an  acid  known  to  form  a  soluble  salt  with 
lime,  such  as  hydrochloric  acid,  would  seem  to  be  all  that  is 
required;  but  in  practice  it  is  found  that  the  action  of  such 


•56 


THE  MANUFACTURE  OF  LEATHER. 


mineral  acids  causes  intense  swelling,  and  the  hide  assumes  a 
transparent,  gelatinous  appearance,  and  loses  its  fibrous  charac- 
ter, thereby  rendering  it  unfit  to  be  converted  into  leather. 
Nevertheless  an  acid  of  some  sort  is  theoretically  the  proper 
thing  to  use;  but  it  must  be  an  acid  that  will  not  disturb  the 
fibrous  nature  of  the  hide,  that  will  form  soluble  salts  with  alka- 
line bases,  and  that  will  not  induce  nor  support  fermentation; 
in  other  words,  such  an  acid  must  be  antiseptic  and  preservative 
in  its  action,  while  at  the  same  time  it  performs  all  the  other 
functions  of  a  bate.  After  a  long  series  of  investigations  and 
laborious  experiments  in  search  of  such  an  acid,  Mr.  Peter  S. 
Burns  and  Mr.  Chas.  S.  Hull,  of  the  Massachusetts  Institute  of 
Technology,  discovered  that  the  naphthalene  sulphonic  acid 
possessed  all  the  properties  requisite  for  such  an  antiseptic  bat- 
ing and  puring  acid.  They  applied  for  and  obtained  a  patent 
for  the  use  of  this  material  for  bating  purposes  in  1891,  and  the 
patent  is  now  owned  and  the  material  manufactured  and  sold 
under  the  name  of  "  C.  T.  Bate"  (coal  tar  bate),  by  the  Martin 
Dennis  Chrome  Tannage  Co.,  of  Newark,  N.  J.  This  "  C.  T. 
Bate"  has  now  been  long  enough  in  use  to  have  its  merits  tested 
most  thoroughly,  and  it  has  been  found  to  fulfill  all  the  expec- 
tations entertained  concerning  it  as  the  long  looked-for  substi- 
tute for  the  nasty,  offensive  and  old-time  manure  bate.  In  its 
commercial  form  the  "  C.  T.  Bate"  is  solid,  but  it  is  readily  sol- 
uble in  water.  Only  a  weak  solution  is  required  to  perform  its 
work  as  a  bate;  it  is  cheap,  clean  and  agreeable  to  handle,  is 
not  poisonous,  and  the  hides  coming  from  the  bating  solution, 
ready  for  the  tan  liquors,  are  smooth,  soft  and  white,  without 
having  lost  any  hide  substance  in  the  bate,  and  with  the  grain 
intact.  Since  the  introduction  of  the  "  C.  T.  Bate"  there  have 
been  other  acids  proposed  and  claimed  to  have  a  similar  charac- 
ter for  bating  purposes.  Prominent  among  these  is  a  mixture 
of  acetic  and  lactic  acids,  but  these  acids  do  not  resist  fermenta- 
tion, but  rather  promote  it;  besides,  acetic  acid  is  a  solvent  for 
gelatine,  while  lactic  acid,  according  to  Fownes,  in  the  presence 
of  water  and  a  ferment  like  animal  membrane  produces  lactous 


BATING. 


157 


fermentation  with  the  formation  of  butyric  acid,  which  is  a  power- 
ful solvent  of  hide  substance.  Another  material  under  the  name 
of  "  borol"  has  been  patented  in  Germany  for  bating  purposes, 
ascribing  to  it  lime-dissolving  and  antiseptic  properties.  It  is 
obtained  by  melting  boracic  acid  with  bisulphates  of  the  metals. 
In  a  description  of  "borol,"  it  is  stated  that  "  in  an  anhydrous 
state  it  represents  a  vitreous  mass,  which  becomes  opaque  by 
absorption  of  humidity;  it  dissolves  readily  in  water;  it  tastes 
and  reacts  acid,  is  to  a  high  degree  a  solvent  of  lime,  and  pre- 
vents putrefaction."  In  1894  a  patent  was  issued  to  P.  Hauff 
in  Germany  for  the  use  of  sulphonic  acid  for  removing  lime  from 
hides  and  skins,  but  this  was  fully  anticipated  by  the  patent 
issued  to  Burns  &  Hull  in  189 1  in  the  United  States.  In  fact, 
it  looks  as  though  Hauff  appropriated  the  American  patent  out- 
right, but  priority  of  invention  in  one  country  destroys  the  valid- 
ity of  a  patent  in  another  country,  and  therefore  Hauff  is  not 
entitled  to  the  discovery  of  this  most  valuable  material.  It  is 
certain  that  American  inventive  genius  is  a  long  way  ahead  in 
discovering  and  applying  new  methods  in  the  industrial  arts 
that  save  both  time  and  labor  in  production  ;  and  it  is  hoped 
that  this  new  American  process  of  bating  will  sooner  or  later 
come  into  general  use,  to  the  great  advantage  and  profit  of  our 
leather  manufacturers. 

Bating  should  always  be  done  in  a  paddle,  as  the  stirring 
motion  allows  the  stock  to  free  itself  of  lime,  and  never  should 
be  done  in  a  stationary  tub. 

There  are  a  large  number  of  tanners  who  still  stick  to  the  old 
form  of  manure  bates,  and  for  their  benefit  we  make  the  follow- 
ing suggestions  and  offer  such  substitutes  as  occur  to  us : 

High-limed  goat  skins  will  not  stand  much  pure.  Wash 
skins  from  lime  in  water  in  which  a  little  sal  ammoniac 
(chloride  of  ammonium)  is  dissolved;  this  will  remove  con- 
siderable of  the  lime  ;  then  give  them  a  light  pure. 

If  the  problem  was  merely  to  remove  the  lime  still  remaining 
in  the  stock,  the  operation  would  be  an  exceedingly  simple  one. 
For  example,  the  stock  could  be  treated  to  a  dilute  solution  of 


158 


THE  MANUFACTURE  OF  LEATHER. 


some  ammoniacal  salt  such  as  chloride  of  ammonia  (sal  am- 
moniac). This  would  remove  the  lime,  leaving  the  stock  white 
and  seemingly  clean.  Or  very  dilute  muriatic  acid  would  be 
effective  for  this  purpose.  The  fermentive  action  of  the  bate 
must  be  consideied  its  essential  property.  The  skins  them- 
selves ferment  with  the  bate,  and  as  considerable  gases  are 
developed  and  become  entangled  in  the  skins  they  rise  to  the 
surface  of  the  liquor  and  are  thrown  out  of  the  action  of  the 
bate.  The  operation  is  therefore  to  some  extent  automatic, 
for  if  they  should  fall  in  the  bate  again,  as  they  sometimes  do 
when  a  thunder-shower  comes  up,  they  would  have  to  undergo 
a  further  ferment  before  raising,  and  under  such  circumstances 
would  be  over-bated  and  probably  run  on  the  grain. 

This  fermentive  action  is  of  course  dangerous. 

The  ferment  developed  produces  weak  organic  acids  which 
act  upon  and  dissolve  the  lime  ;  at  the  same  time  the  stock  is 
reduced,  becomes  soft  and  slippery,  the  pores  are  opened  so 
that  the  dirt,  lime,  greasy  soap,  fine  hairs,  etc.,  can  be  worked 
out  freely  upon  the  beam,  thus  thoroughly  cleansing  the  stock 
preparatory  to  tanning. 

The  best  time  for  fine-hairing  is  after  the  drenching,  as  the 
grain  of  the  skins  is  then  cleaner,  and  the  fine  hairs  more  easily 
seen.    This  enables  the  workmen  to  get  better  results. 

Pigeon  manure  is  considered  the  best  bate  for  calfkid  and 
sides,  and  should  not  be  used  over  95  degrees  in  winter  and  90 
degrees  F.  in  summer.  The  bran  drench  should  not  be  above 
the  temperature  referred  to,  and  is  used  in  all  kid-tannages  ex- 
cept chrome. 

The  period  which  the  hides  or  skins  remain  in  the  bating 
solution  is  dependent  upon  the  temperature  of  the  bate  and  the 
thickness  of  the  material  subjected  to  its  action. 

Borax  and  boracic  acid  make  good  bates  when  dissolved  in 
water;  they  work  out  the  lime,  but  do  not  eat  away  the  hide 
substance. 

Puring  as  conducted  by  manufacturers  of  light  leathers,  is 
done  for  the  purpose  of  removing  the  lime  from  the  skins  and 
preparing  them  for  tanning. 


BATING 


159 


The  method  pursued  is  to  ferment  an  emulsion  of  bran, 
middlings  or  flour,  till  it  is  quite  acid,  then  putting  the  pelts  or 
skins  into  this  fermenting  mixture.  The  acids  formed  by  the 
fermentation  make  soluble  salts  of  lime  in  the  skins,  and  the 
bulk  of  water  dissolves  the  salts  of  lime  out  of  the  skins  by  the 
subsequent  washing.  During  this  operation  there  is  quite  a 
quantity  of  carbonic  acid  gas  generated  which,  collecting  under 
the  skins  or  pelts,  causes  them  to  rise.  When  the  skins  are 
first  thrown  into  the  drench  they  sink  to  the  bottom,  but  as  the 
fermentive  action  generates  the  carbonic  acid  gas,  they  come 
to  the  surface,  and  the  liquid  becomes  covered  with  a  white 
foam.  This  has  no  connection  with  the  drenching  proper, 
being  only  an  effect  of  the  fermenting  action  and  the  liberation 
of  gas.  The  workmen  can  best  judge  when  pelts  are  drenched 
by  their  appearance  and  feel.  There  are  several  objections  to 
this  fermentation  of  bran  for  drenching,  it  being  a  dirty,  long 
and  uncertain  operation.  The  decomposing  ferments  that 
break  up  the  starch  in  the  bran  into  acids  permeate  the  skins, 
and  are  carried  over  into  the  tanning  liquids,  causing  an  acid 
fermentation  in  them.  There  is  also  a  risk  of  weeds,  etc.,  which 
contain  tannin,  being  in  the  bran  or  middlings,  depositing  a 
certain  amount  of  tannin  in  the  skins  while  in  the  drench  bath, 
causing  spotted  and  cloudy  results  in  the  tawed  or  tanned 
stock  which  afterwards  produces  uneven  coloring.  Drenching 
is  an  essential  operation  to  the  preparation  of  nice  leather.  To 
leave  any  lime  in  the  stock  makes  hard,  brittle  and  cracky 
leather. 

In  tanning  with  salts  and  alum  it  is  absolute  ruin,  as  the 
alum  loses  some  of  its  sulphuric  acid,  making  sulphate  of  lime 
(common  gypsum),  which  makes  the  skins  harsh  and  hard,  it 
being  almost  impossible  to  soften  them. 

To  leave  lime  in  the  skins  to  be  tanned  with  tannin  or  other 
vegetable  extracts  means  the  production  of  brown  spots,  darker 
color  and  a  brittle  grain.  Leaving  lime  in  skins  to  be  used  in 
the  chrome  process  means  the  production  of  sulphate  of  lime 
in  them,  due  to  the  acid  used  in  the  first  bath  with  bichromate 
of  potash,  also  producing  a  brittle  grain  and  hard  leather. 


THE  MANUFACTURE  OF  LEATHER. 


The  removal  of  lime  is  essential  in  making  good  leather,  yet 
to  remove  it  by  means  of  the  bran  drench  is  dirty  and  trouble- 
some. 

Hides  that  are  intended  for  sole  leather  are  generally,  after 
they  are  unhaired  and  fleshed,  merely  washed  or  rinsed,  then 
immediately  put  into  tan  liquor,  and  handled  until  colored,  then 
shifted  on  consecutively.  Some  tanners  who  have  the  facility, 
cleanse  them  more,  and  by  this  means  get  a  better  color,  but 
still  there  is  a  large  quantity  of  lime  in  the  interior,  which  sours 
the  liquors,  and  if  they  are  not  soon  removed  from  it,  the  hide 
gets  soft  and  flabby  by  the  loss  of  gelatine  which  it  causes. 
This  would  be  prevented  if  the  hides,  after  fleshing,  were  put 
into  a  bath  that  would  extract  the  lime,  and  yet  extend  the 
fibrine,  so  that  it  grows  continuously,  and  after  well  scudding  it 
will  be  more  developed,  and  better  fitted  to  imbibe  tannic  acid. 

Dressing  leather  is  universally  bated  in  the  United  States, 
and  many  other  countries,  but  it  is  supposed  no  bates  are  used 
by  the  French,  who  excel  all  others  for  qualities  of  upper 
leather.  It  should  be  said  they  do  not  use  excrement,  which 
we  say  cannot  be  done  without,  yet  we  have  seen  upper  leather 
manufactured  in  the  United  States  without  its  use,  far  superior 
to  any  where  it  has  been  used.  We  know  that  where  lime  is 
used  for  depilating,  it  must  be  extracted  before  good  upper 
leather  can  be  made.  This  should  be  done  by  a  non-impover- 
ishing agent,  so  that  the  hide  is  not  reduced,  but  is  left  with 
the  whole  body  to  be  matured  and  utilized. 

When  the  unhairing  has  been  properly  done,  all  hides  and 
skins  should  be  properly  cleansed  from  the  depilatory  agent, 
whatever  that  agent  may  have  been.  Lime  is  not  so  deleterious 
to  sole  leather  as  to  offal  used  in  some  countries  for  insoles, 
but  still  it  defiles  the  liquors  and  does  not  improve  the  sole 
leather.  All  sole  leather  should  be  thoroughly  cleansed  from 
lime ;  however,  we  would  not  advise  that  sole  leather  be  bated 
with  the  excrement  of  animal,  which  destroys  a  large  percent- 
age of  the  gelatine.  A  good  bate  for  sole  leather  and  one 
which  is  used  in  many  of  the  large  tanneries  of  this  country, 


BATING. 


161 


although  kept  a  secret,  is  that  discovered  by  Trumbull  in  1847, 
which  consists  of  sugar,  or  molasses  ;  the  proportion  used  being 
about  6  pounds  to  100  gallons  of  water.  This  solution  forms  a 
soluble  saccharate  of  lime.  We  have  seen  some  excellent  sole 
leather  produced  by  the  use  of  this  bate,  a  much  greater  addi- 
tional weight  being  secured  than  could  otherwise  be  obtained. 

The  object  should  be  to  cleanse  the  hide  or  skin  from  the 
deleterious  materials  used  in  the  unhairing  process.  We  pre- 
fer the  term  puring,  i.  e.t  get  the  hide  or  skin  pure  from  all 
alkaline  matter  without  decomposing  it.  It  will  then  be  full, 
soft,  and  velvety,  instead  of  an  empty  rag.  We  read  some- 
times that  a  calf-skin  should  be  so  reduced  that  you  may  pull 
it  through  a  finger  ring;  but,  to  test  this,  let  a  calf-skin  be 
tanned  as  it  comes  from  the  butcher.  After  cleansing  well 
from  the  blood  and  dirt,  can  it  then  be  pulled  through  a  large 
ring,  and  will  not  the  leather  be  firm,  stout,  and  good? 

The  practice  of  reducing  the  hide  or  skin  is  so  universal 
among  tanners  and  so  consolidated,  that  it  requires  electrical 
agency  to  dispel  the  illusion  ;  even  those  who  are  the  most 
desirous  to  get  an  improved  mode  of  puring  hides  and  skins 
from  the  depilitant,  cannot  believe  it  can  be  accomplished  if 
the  pelt  is  not  reduced  so  as  to  leave  it  a  mere  rag,  as  is  done 
by  excrement  bates,  which  consume  the  gelatine  wrhile  com- 
bining with  the  lime. 

It  is  useless  for  us  to  profess  anxiety  for  improvements  in  our 
manufactures  and  expect  to  find  our  goods  acted  upon  by  im- 
proved methods  to  appear  the  same  in  every  stage  as  they  do 
by  old  methods,  if  the  altered  mode  produces  no  different  ap- 
pearance. What  different  result  can  be  expected  at  the  finish, 
and  as  bating  has  much  to  do  with  weight  and  quality,  how  can 
weight  and  quality  be  improved,  if  the  pelt  is  persistently 
reduced  ? 

What  are  the  impurities  but  lime,  fat,  and  dirt,  commonly 
called  scud,  and  the  fine  undergrowth  of  hair?    But  even  the 
undergrowth  of  hair  should   have  been  so  loosened  by  the 
depilitant  that  no  difficulty  should  arise  in  removing  it  in  scud- 
1 1 


THE  MANUFACTURE  OF  LEATHER. 


ding.  The  lime  and  fat  should  be  assimilated  by  the  pure, 
which  with  the  dirt  would  form  a  kind  of  soap,  and  would  yield 
to  the  scudding  knife  and  leave  the  pelt  intact  without  reduc- 
ing it,  as  all  usual  bates  do  by  attacking  the  fluid  gelatine 
which  it  draws  from  the  hide  or  skin.  And  from  force  of  habit 
tanners  say  it  is  properly  reduced  or  bated,  and  if  this  fluid 
gelatine  is  not  extracted,  they  say  it  is  not  sufficiently  reduced 
and  will  not  make  good  leather  for  the  purpose  required. 

The  time  is  approaching  when  this  axiom  will  be  discarded. 
The  necessity  is  even  now  apparent  by  the  large  imports  of 
light  leather  taking  the  place  of  goods  that  we  manufactured 
ourselves  in  olden  times  for  our  own  consumption.  Very  light 
goods  are  required  for  some  branches  of  the  trade,  and  it  is 
said  this  can  only  be  got  by  reducing  the  skin  in  the  bate ;  but 
if  the  proper  skins  were  selected  and  manufactured  with  the 
whole  constituents  left  in,  superiority  would  be  obtained,  for 
the  fluid  gelatine  is  the  lubricator  of  the  fibrines  in  life,  and  is 
as  important  an  agent  in  preserving  fineness  of  texture  and 
mellowness,  flexibility  and  toughness  of  leather  when  finished. 

While  we  practice  bating  for  sheep,  goat,  calf,  kip,  and  cow 
or  yearling,  for  producing  a  soft  pliable  leather,  we  do  not  as  a 
rule  use  bates  for  sole  leathers,  which  are  required  to  be  firm 
and  solid  ;  these  are  generally  only  washed  or  rinsed  from  the 
lime  and  lightly  scudded,  then  put  into  the  handlers  and  moved 
till  they  are  colored,  souring  the  liquors  and  making  them 
worse  than  useless.  We  would  advise  puring  these  from  lime- 
also,  though  in  a  different  degree  than  for  light  dressing  or 
dyeing  goods,  and  the  leather  though  not  harsh  would  be  firm, 
tough,  and  would  not  grind  away  like  that  in  which  a  large 
quantity  of  lime  remained  ;  the  weight  also  would  be  improved, 
for  the  antagonism  between  the  alkali  lime  and  the  tannic  acid 
when  they  first  come  in  contact,  results  in  the  decomposition 
of  gelatine,  until  the  alkaline  properties  are  overcome. 

Not  being  able  to  get  colors  right  in  glove  leathers  is  gen- 
erally due  to  poor  bating;  lime  is  the  great  enemy.  When 
skins  are  pickled  a  chemical  change  takes  place,  the  lime  put 


BATING. 


in  the  skin  being  changed  to  sulphate  of  lime  by  the  sulphuric 
acid,  and  this  clogs  the  pores  of  the  skin  so  that  no  tan  liquor 
can  get  in,  but  the  lime  can  work  out  and  act  upon  the  colors. 
Sulphate  of  lime  is  not  soluble  in  water.  It  is  soluble  in  lactic 
acid,  and  it  is  for  this  reason  that  tanners  who  use  sour  liquors 
have  no  trouble  with  lime,  as  the  sour  liquor  contains  lactic 
acid.  Lime  left  in  is  sure  to  produce  hard,  brittle  leather. 
On  the  other  hand  bating  must  be  done  with  care. 

Among  the  many  ways  of  earning  a  livelihood  is  that  of  col- 
lector of  dog-pure,  an  individual  frequently  to  be  met  with  in 
the  tannery  districts  of  Paris,  where  he  goes  to  dispose  of  his 
ware. 

In  common  with  the  excrements  of  other  carnivorous  ani- 
mals, that  of  the  dog  contains  an  acid,  which,  it  is  claimed,  has 
hitherto  defied  artificial  production,  and  has  the  property  of 
"cutting"  the  grease  and  fat  adhering  to  fresh  skins;  it  also 
softens  and  bleaches  the  skin,  and  first  quality  dog-pure  is 
valued  above  all  other  dung  for  the  reason  that  the  acid  it  con- 
tains is  just  powerful  enough  to  produce  these  results  without 
injuring  the  delicate  fibre  of  the  skin.  Dog-pure  is  used  by 
manufacturers  of  fine  sheep  leathers,  especially  those  making 
leathers  for  covering  corset  steels  or  for  purse-linings,  and 
many  of  these  establishments  are  said  to  have  their  regular 
salaried  collectors. 

The  pure  is  prepared  for  use  by  dissolving  in  water  main- 
tained at  a  temperature  of  5  to  lO°  C.  for  several  weeks. 
When  "  ripe,"  the  "  preserves,"  as  the  appetizing  mixture  is 
technically  termed  in  France,  is  "  skimmed,"  that  is,  the 
"  cream "  removed  for  use,  the  residue  consisting  of  small 
bones  and  other  detritus,  which  dogs  have  an  unfortunate  habit 
of  swallowing,  and  which  would  be  apt  to  injure  the  skins. 
The  latter  are  then  placed  to  soak  in  the  decoction,  where  they 
acquire  that  velvety  softness  so  much  appreciated. 

The  theory  of  dung  bating,  while  obscure,  is  that  a  chemical 
combination  is  formed  with  lime  under  the  influence  of  the 
agents  of  which  the  droppings  are  composed,  the  ammoniacal 


THE  MANUFACTURE  OF  LEATHER. 


chloride  parting  with  its  chlorine  to  form  the  chloride  of  lime, 
which  is  readily  dissolved  in  water. 

Hydrochloric  acid  possesses  the  property  of  dissolving  lime 
in  the  manner  accomplished  by  the  bate,  as  was  shown  by 
MacBride  in  1774. 

Carbonate  of  ammonia  was  employed  by  Warrington  in  1841, 
for  accomplishing  the  purposes  of  the  bate. 

In  addition  to  the  substances  named,  carbolic  acid,  sulphuric 
acid,  dilute  phosphoric  acid,  organic  acids,  muriate  of  ammonia, 
alum,  etc.,  are  employed. 

Some  of  the  objections  to  the  present  method  of  bating  in 
addition  to  its  expensiveness  are:  — 

1.  The  disagreeable  odor  and  uncleanliness  attendant  upon 
the  use  of  the  excrement  of  animals. 

2.  The  difficulty  in  obtaining  properly  skilled  labor  to  super- 
intend the  operation,  which  is  necessary  because  of  the  tendency 
to  decomposition  produced  by  the  use  of  animal  excrements. 
This  decomposition  is  designated  by  tanners  generally  as  "  run- 
ning away,"  and  means  literally  that  the  skins  are  frequently 
decomposed  into  a  state  of  liquid  putridity,  and  only  skilled 
tanners  by  watching  the  vats  can  detect  the  approach  of  such  a 
condition. 

3.  Then  there  is  such  great  difference  in  the  strength  of  the 
same  kind  of  animal  excrements,  as  that  of  dogs  for  instance  (due 
to  the  different  varieties  of  food  upon  which  they  have  been  fed, 
vegetables,  bones,  etc.),  that  practically  no  definite  period  can 
be  positively  set  within  which  it  is  safe  to  let  the  excrement 
operate. 

4.  The  influence  which  the  electrical  condition  of  the  atmo- 
sphere has  upon  stock  in  the  bate,  which  is  frequently  damaged 
or  spoiled  during  thunder-storms. 

The  bating  is  usually  accomplished  by  placing  the  hides  or 
skins  in  a  vat  having  a  circular  and  tight  bottom,  over  which 
vat  is  arranged  a  revolving  paddle  wheel  marked  1  in  Fig.  35, 
which  dips  into  the  solution  contained  in  the  vat,  thereby  agitat- 
ing it  and  maintaining  the  sides  or  skins  in  constant  motion, 


THE  MANUFACTURE  OF  LEATHER. 


thus  hastening  the  work  of  bating  and  greatly  lessening  the 
time  and  danger  of  spoiling  the  material  in  the  bate. 

After  the  sides  or  skins  have  been  properly  treated  they  are 
placed  in  the  interior  of  the  wheel  or  drum,  marked  2  in  Fig. 
35,  and  washed  with  clear  water  for  a  few  minutes. 

The  English  wheels  used  for  agitating  the  bate  liquor,  and 
the  wheel  used  for  washing  the  sides  or  skins,  are  shown  in  per- 
spective view  in  Fig.  35. 

When  the  sides  show  the  right  condition  scouring  is  proceeded 
with,  this  operation  being  effected  either  by  hand  or  by  a  hide- 
working  machine,  or  the  scouring  may  be  performed  by  the 
Vaughn,  Whitney  or  other  macnines  shown  in  Figs.  28  to  34, 
at  the  time  of  unhairing  and  fleshing,  if  the  latter  operations  be 
performed  by  machinery. 

The  object  of  this  scouring,  which  should  not  be  confounded 
with  the  scouring  which  is  to  be  hereafter  described  for  remov- 
ing the  bloom  from  the  hides  after  tanning,  is  to  free  the  hides 
from  lime  and  dirt  and  fit  them  for  the  reception  of  the  tannin 
ooze  to  which  they  are  first  subjected  in  the  handlers. 

In  the  preparation  of  sole  leather  the  hides  are  scraped  on  the 
grain  side  with  a  curved  knife  in  order  to  cleanse  them  from 
lime  remaining  in  the  pores  after  the  last  soaking,  and  this 
operation  is  termed  "  graining." 

FINAL  SOAKING  BEFORE  PLACING  THE  HIDES  IN  THE  OOZE. 

After  treating  the  hides  and  skins  in  the  above  manner,  and 
being  assured  by  the  previously  described  tests  that  they  have 
been  sufficiently  soaked,  it  is  only  necessary  to  replace  them  in 
water  for  5  to  12  hours  longer.  The  safest  indication  of  the 
hides  and  skins  being  ready  for  the  ooze  is  that,  when  passing 
the  fingers  over  them,  strokes  remain  as  indentations. 


CHAPTER  X. 


HANDLING  AND  PLUMPING. 
HANDLING. 

The  occasional  removal  of  hides  or  sides  from  the  vat,  and 
then  replacing  them,  also  the  agitation  of  the  stock  at  stated 
times  while  remaining  in  the  liquor  in  the  vat,  is  termed  "  hand- 
ling," the  object  of  which  is  to  equalize  the  action  of  the  lime 
in  the  unhairing  process,  the  bate  in  the  bating  process,  and  of 
the  weak  liquor  or  ooze  in  the  first  stage  of  tanning. 

The  old  manner  of  handling  hides,  like  most  of  the  primitive 
methods  of  the  tanner's  art,  was  exceedingly  slow  as  well  as 
laborious  ;  but  of  late  years  numerous  appliances  have  been  per- 
fected for  mechanically  performing  this  work,  by  means  of  which 
the  stock  is  handled  with  great  facility  and  at  the  expenditure 
of  but  little  labor.  One  old  method  was  to  haul  up  the  sides  by 
hand  from  the  vat  and  pile  them,  and  in  this  condition,  allow 
them  to  press  and  drain,  and  then  after  a  sufficient  time  throw 
them  again  into  the  vat. 

Another  and  later  method  was  to  "  shift  "  or  change  the  sides 
from  one  vat  over  into  another  by  means  of  hooks. 

Handling  and  transferring  the  sides  by  the  medium  of  a 
revolving  device,  such  as  the  reel,  is  an  old-fashioned  method 
which  has  not  yet  become  obsolete  ;  but  which  continues  to  be 
employed  in  the  majority  of  both  small  and  large  tanneries  in 
this  country;  in  large  tanneries  the  reel  being  operated  by 
power. 

This  manner  of  handling  seems  to  be  both  convenient  and 
economical,  and  as  there  are  but  few  objections  that  can  be 
urged  against  it,  there  are  at  present  but  slight  chances  of  it 
being  generally  abandoned  for  later  processes,  of  which  we  have 
a  great  variety. 

(  167) 


i68 


THE  MANUFACTURE  OF  LEATHER. 


There  are  two  modes  in  vogue  of  connecting  the  sides,  which 
are  to  be  handled,  with  the  reel.  One  is  to  tie  them  together 
with  strings  and  the  other  is  to  connect  them  with  a  tie-loop ; 
but  the  first  method  is  most  commonly  employed,  and  is  the 
least  expensive. 

The  hand-reel  is  about  three  feet  high,  and  is  made  as  light 
as  possible,  consistent  with  requisite  strength,  in  order  that  it 
may  be  readily  moved  by  two  men  from  one  vat  to  another. 

When  in  use  the  reel  is  placed  on  the  alleys  intermediately 
between  the  two  vats  in  which  the  hides  are  to  be  handled,  and 
the  sides  or  hides  are  drawn  over  the  drum  by  the  workman 
who  turns  the  crank  attached  to  the  shaft  on  which  the  drum  is 
fastened.  Two  men  are  required  to  operate  this  reel,  one  to 
adjust  the  sides  or  hides  in  the  head  vat,  and  the  other  to  work 
the  crank. 

Another  form  of  handler  in  use  is  known  as  the  rocker 
handler,  and  it  consists  of  a  frame  constructed  of  wood,  and 
hung  by  pivots  in  the  centre  of  the  top  of  the  vat  so  as  to  give 
a  dipping  movement  of  7  or  8  in.  to  each  end  of  the  frame,  and 
the  sides  are  hung  over  sticks  placed  across  the  frame  from  the 
two  sides,  motion  being  usually  imparted  to  the  handler  from 
shafting  placed  overhead. 

The  apparatus  shown  in  Figs.  36  and  37  was  invented  by  L. 
C.  England,  in  187 1,  and  consists  in  a  good  method  of  keeping 
the  stock  suspended  in  the  liquor,  so  that  all  parts  may  be 
brought  into  constant  contact  with  the  ooze,  and  its  employ- 
ment in  liming,  bating  and  handling  should  produce  a  smooth 
grain  and  good  quality  of  leather. 

Fig.  36  is  a  perspective  view  of  the  apparatus,  showing  it 
removed  from  the  vat.  Fig.  37  is  a  vertical  section  of  the  same, 
showing  it  applied  to  a  tan-vat. 

The  frame  F  is  made  to  conform  to  the  interior  of  the  vat, 
and  consists  of  the  upper  and  lower  rails,  S,  S1,  S2,  and  S3,  and 
the  cross  rails  E,  El,  E2,  and  £3,  which  are  joined  together  by 
means  of  the  uprights  U,  Ul,  U2,  U3,  and  [/*,  and  which  uprights 
serve  as  guides  to  retain  the  frame  in  a  horizontal  position. 


HANDLING  AND  PLUMBING. 


169 


The  frame  F  is  also  provided  near  the  lower  part  with  two 
diagonal  braces,  B,  B1,  at  the  point  of  intersection  of  which  is 
an  upright  shaft  R,  to  which  power  is  applied  to  operate  the 
frame,  the  braces  serving  to  agitate  the  liquors. 

Fig.  36. 


The  series  of  bars  d  d  d,  are  held  by  the  binders  T,  T\  which 
prevent  them  from  shifting  as  the  frame  moves  downward. 


THE  MANUFACTURE  OF  LEATHER. 


The  stock  is  hung  on  the  movable  bars  d  d  d  with  head  and 
butt  down,  and  the  proper  liquors  supplied. 

The  frame  is  placed  in  the  vat  so  that  the  top  of  the  stock 
resting  on  the  bars  may  be  about  eight  or  ten  inches,  more  or 
less,  below  the  surface  of  the  liquors. 

The  whole  frame  is  then  caused  to  move  upward  in  a  vertical 
line  of  a  few  inches,  four  to  six  being  sufficient,  but  should  not 
be  allowed  to  raise  the  stock  above  the  surface  of  the  liquor. 
The  stock  being  loose  on  the  bars  will,  when  the  frame  moves 
downward,  be  left  suspended  in  the  liquor,  entirely  free  from 
contact  with  the  bars,  thus  allowing  the  liquor  free  access  to 
the  parts  of  the  stock,  which,  when  the  frame  is  at  rest,  adheres 
to  the  bars  on  which  it  is  placed.  The  upward  and  downward 
vertical  motion  given  to  the  frame  will  keep  the  stock  at  nearly 
the  highest  point  to  which  it  is  raised  by  the  first  stroke  of  the 
frame  upward,  the  frame  being  moved  faster  than  the  stock 
would  sink  in  the  liquor  if  unobstructed.  Every  returning 
upward  stroke  of  the  frame  will  carry  the  stock  back  to  the 
highest  point  again.  The  frame  is  caused  to  move  only  so  fast 
as  will  have  the  desired  effect,  and  at  intervals,  as  occasions 
may  suggest. 

The  specific  gravity  of  the  frame  and  stock  being  very  small, 
the  power  required  to  give  the  necessary  motion  while  they 
are  submerged  in  the  liquor  is  correspondingly  small. 

The  paddle  wheels  for  handling  shown  in  Chapter  IX.,  Fig. 
35,  which  were  also  invented  by  L.  C.  England,  in  1867, 
are  largely  employed  in  handling  heavy,  medium,  and  light 
leathers. 

These  wheels  work  within  three-quarters  of  an  inch  of  the 
sides  and  are  usually  five  and  a  half  feet  in  diameter,  and  have 
eleven  paddles  about  seven  eighths  of  an  inch  thick,  and  spaced 
equidistant  apart,  which  is  about  eighteen  inches  between 
centres  at  the  outer  edge. 

The  vats  in  which  the  wheels  revolve  have  the  bottom  con- 
cave to  conform  to  the  convexity  of  the  wheels  which  are  placed 
over  the  centre  of  the  vats,  so  that  the  wheels  dip  about  eight 


HANDLING  AND  PLUMBING. 


171 


inches  in  the  liquor,  and  thereby  cause  a  gentle  but  thorough 
agitation  of  the  ooze  and  stock,  which  moves  in  an  opposite 
direction  from  that  of  the  wheels. 

The  motion  of  the  wheels  causes  the  stock  to  move  up  in 
front,  pass  under  the  wheels,  and  down  on  the  concave  bottom 
to  the  back  of  the  vat,  and  thus  by  means  of  the  paddles,  and 
the  constant  changing  position  of  the  stock,  a  thorough  and 
gentle  agitation  is  maintained.  But  if  the  bottom  of  the  vat 
should  be  made  square,  the  agitation  would  be  too  great  to 
answer  the  purpose. 

No  fixed  length  of  time  can  be  set  for  running  these  wheels, 
as  the  period  depends  upon  the  stock  being  handled ;  light 
sides,  as  those  used  for  upper  leather,  being  handled  for  a 
shorter  period  and  not  so  often  as  the  heavy  whole  hides  em- 
ployed for  making  enameled  and  patent  leathers. 

The  wheel,  should  for  no  class  of  leather  be  run  at  a  greater 
speed  than  eighteen  revolutions  to  the  minute,  and  the  motion 
should  be  steady  and  regular.  Cog-gearing  is  best,  and  pos- 
sesses a  great  advantage  over  belting,  as  the  latter,  from  the 
slow  motion  required,  often  becomes  troublesome. 

Wheels  of  this  kind  are  generally  arranged  in  a  line,  as  shown 
in  Fig.  35,  and  sometimes  so  constructed  that  any  one  of  them 
can  be  thrown  out  of  gear,  by  means  of  a  clutch  connected  with 
the  loose  pinion  on  the  shaft. 

It  has  at  times  been  tried  to  apply  these  wheels  to  quicken 
the  after-process  of  tanning;  but  while  they  answer  for  light 
leathers,  it  is  the  opinion  of  some  who  have  experimented  with 
them  upon  heavy  leathers  that  they  will  not  answer;  but  not- 
withstanding this  opinion,  we  have  seen  them  successfully  em- 
ployed at  Newark,  N.  J.,  and  other  places,  for  tanning  heavy 
whole  hides  to  be  used  in  the  manufacture  of  enameled  leather. 

This  wheel  furnishes  a  most  simple  and  effectual  mode  of 
moving  the  incipient  leather  in  the  liquor,  and  does  away  en- 
tirely with  the  necessity  of  handling  by  hand,  facilitates  the 
after-process  of  tanning,  economizes  in  labor,  forms  a  hand- 
some grain,  and  in  all  respects  improves  the  quality  and  texture 
of  the  leather. 


THE  MANUFACTURE  OF  LEATHER. 


Methods  of  handling,  such  as  lacing  it  together  and  drawing 
the  stock  through  rollers,  or  placing  the  hides,  sides,  or  skins 
upon  a  web,  unlaced  and  feeding  the  stock  to  the  rollers,  are 
not  now  employed  in  this  country.  However,  they  continue  to 
be  profitably  used  for  some  classes  of  leathers  by  a  few  Euro- 
pean tanners,  the  theory  being  that  by  pressing  the  liquor  out 
of  the  pores  in  handling  upon  re-immersion,  the  liquor  into 
which  the  stock  is  placed  acts  more  quickly  and  in  the  end 
produces  a  heavier  weight  than  is  ordinarily  obtained. 

In  the  manufacture  of  grain  and  split  leathers  the  sides  are 
tacked  upon  sticks  and  handled  into  stronger  liquor  about  every 
three  days,  and  it  might  here  be  stated  that  any  method  of 
handling  which  allows  both  the  grain  and  flesh  sides  to  be  uni- 
formly exposed  to  the  action  of  the  liquor  will  fill  all  the  re- 
quirements, provided  there  is  a  gentle  agitation  of  the  fibre  at 
occasional  periods. 

In  some  portions  of  the  country  the  handling  is  performed  by 
placing  the  stock  in  the  interior  of  a  large  revolving  drum 
about  10  feet  in  diameter,  one-half  of  which  turns  in  the  liquor 
of  the  vat,  the  centre  shaft  upon  which  the  drum  is  supported 
turning  in  bearings  resting  upon  the  top  of  the  vat. 

The  interiors  of  these  drums  are  best  divided  into  three  or 
four  compartments,  as  it  is  easier  upon  the  green  stock  than 
allowing  it  to  be  treated  in  an  unpartitioned  wheel,  and  besides 
the  operation  of  the  contrivance  is  facilitated  by  retaining  a 
portion  of  the  contents  near  the  centre. 

In  Gorsline's  apparatus  for  handling,  the  sides  or  skins  are 
placed  in  the  vat  resting  upon  five  straps,  having  cross  slats 
attached  to  them,  and  one  end  of  each  of  the  straps  is  attached 
to  the  top  of  the  vat,  and  when  it  is  desired  to  raise  the  pack, 
the  centre  strap  is  wound  around  a  drum  which  gradually  raises 
it,  and  as  it  approaches  the  top,  the  operator  standing  upon  the 
alley  can  easily  seize  the  hides  and  throw  them  out. 

The  slats  slide  over  the  centre  strap  which  winds  upon  the 
drum,  thus  preventing  them  from  striking  the  frame  and  stop- 
ping the  machine. 


HANDLING  AND  PLUMPING. 


173 


In  raising  the  pack  the  inclined  position  it  assumes  has  a 
tendency  to  wash  off  the  sediment  or  bloom,  presenting  the 
same  advantage  in  this  respect  as  in  handling  by  hook  in  the  • 
ordinary  way. 

This  contrivance  is  better  adapted  for  handling  kips  and 
skins  than  for  heavy  sides  or  hides. 

PLUMPING. 

The  swelling  or  "  plumping"  follows  the  unhairing  and  flesh- 
ing, and  after  the  bating  of  the  hides,  which  has  been  described, 
and  it  consists  of  a  more  or  less  prolonged  immersion  in  an  acid 
liquor,  which  is  gradually  increased  in  strength.  Its  essential 
action  consists  in  completing  the  swelling  of  the  cells,  distend- 
ing the  pores,  and  thus  favoring  the  absorption  of  the  tannin. 
A  secondary  action  takes  place ;  it  is  a  commencement  of  tan- 
ning due  to  the  presence  of  a  certain  quantity  of  tannin  in  the 
liquor ;  the  swelling  being  due  to  the  action  of  acetic  acid,  and 
of  the  lactic  acid.  Both  acids  are  products  of  decomposition 
and  oxidation  of  the  non-tannins,  such  as  sugars,  gums,  etc. 

Some  wood  vinegar  may  be  added  to  the  sour  tan  liquor  in 
order  to  accelerate  the  swelling.  This  process  does  not  cause 
any  damage  to  the  quality  of  the  leather ;  but  some  tanners 
replace  the  acetic  acid  by  sulphuric  acid,  which,  at  an  equal 
degree  of  acidity,  costs  considerably  less.  This  practice  is 
prejudicial  to  the  quality  of  the  leather.  It  is  true  that  the 
swelling  is  satisfactorily  produced,  and  the  leather  looks  well, 
but,  prepared  in  this  manner,  it  retains  traces  of  sulphuric  acid 
which  corrode  it  internally  after  a  time,  and  make  it  very 
brittle  and  more  subject  to  alteration  by  moisture,  and  there  are 
other  defects  which  will  be  mentioned  shortly. 

The  "  plumping"  process  is  applied  to  the  heavier  classes  of 
hides  only,  such  as  those  employed  for  the  manufacture  of  sole- 
leather,  upper-leather,  harness,  belting,  patent  and  enamel 
leathers,  etc. 

PLUMPING  BY  MEANS  OF  SOUR  LIQUOR. 

There  are  at  present  two  methods  in  common  use  by  which 


•74 


THE  MANUFACTURE  OF  LEATHER. 


this  plumping  is  accomplished,  as  has  been  stated,  In  one  of 
these  the  tanning-liquor  which  has  been  in  use  for  some  time, 
is  made  use  of  under  the  name  of  "tailings,"  or  sour  liquor,  in 
which  the  hide  having  been  properly  prepared  is  first  placed. 

The  fresh  tan-liquors  after  a  short  time  become  changed  in 
their  character  and  nature,  and  the  resultant  is  a  liquid  in  which 
we  find  tannic,  gallic,  and  acetic  acids  in  varying  proportions, 
combined  with  decaying  vegetable  and  putrescent  animal  mat- 
ter; but  the  presence  of  the  latter  substances  seriously  interferes 
with  the  exhibition  of  those  active  principles  which  the  tanner 
seeks  to  utilize  from  his  sour  liquors,  and  it  is  the  presence  of 
this  decomposed  matter  that  forms  the  only  objection  to  this 
method  of  plumping  hides,  and  from  which  the  principal  dan- 
ger arises,  which,  while  not  great,  still  requires  watchfulness. 

The  second  method  of  plumping,  which  will  be  enlarged 
upon  in  the  next  section  of  this  chapter,  is  to  steep  the  hides  in 
a  cold,  dilute  sulphuric-acid  liquor. 

But  while  the  latter  method  expedites  the  work,  it  has  the 
effect  of  rendering  the  leather  harsh,  liable  to  be  brittle,  and 
gives  a  dark  grain  to  the  same,  it  being  conceded  by  all  practi- 
cal tanners  that  the  process  in  which  the  plumping  is  wrought 
by  the  presence  of  the  acetic  acid  in  the  tailings  is  far  prefera- 
ble, could  the  same  be  divested  of  the  trouble  arising  from  the 
decaying  animal  and  vegetable  substances  present  in  all  tan- 
ning-liquors which  have  been  used  for  any  length  of  time. 

H.  J.  Botchford,  of  Leyden,  N.  Y.,  proposes  to  remedy  this 
by  subjecting  the  sour  liquors  to  a  distillation  in  a  still  suitably 
constructed,  by  which  the  acetic  and  other  volatile  acids  are 
recovered  in  a  pure  form,  freed  from  the  other  substances  of 
the  liquors.  The  distillate  thus  resulting  is  now  taken,  and,  in 
a  properly  dilute  form,  is  again  used  as  a  liquid  in  which  the 
plumping  of  the  hides  may  be  very  expeditiously  and  satisfac- 
torily accomplished. 

In  the  practical  working  of  this  process  the  distillation  is 
best  accomplished  by  the  use  of  a  still  in  which  the  liquors 
from  which  the  acid  products  are  to  be  recovered  are  heated 


HANDLING  AND  PLUMPING. 


'75 


by  means  of  a  steam-worm  coiled  within  the  body  of  the  retort 
containing  the  said  liquors,  the  vapors  of  the  acids  thus  liber- 
ated being  conducted  from  the  head  of  the  retort  through  a 
tubular  condenser,  the  temperature  of  which  is  maintained  at  a 
sufficiently  low  point  for  the  proper  condensation  of  the  acid 
vapors  by  surrounding  the  same  with  water  at  a  low  degree  of 
heat;  but  any  apparatus  ordinarily  termed  a  "still"  will  an- 
swer, as  long  as  its  materials  are  arranged  to  be  proof  against 
the  attack  of  the  acids  to  be  recovered,  and  the  heat  of  which 
can  be  maintained  equally. 

PLUMPING  BY  MEANS  OF  SULPHURIC  ACID. 

In  1773,  David  MacBride,  a  physician  of  Dublin,  introduced 
the  employment  of  sulphuric  acid  for  swelling  or  plumping 
hides,  and  though  it  may  appear  strange  that  such  an  improve- 
ment should  have  been  made  by  a  member  of  the  medical  pro- 
fession, still  this,  like  many  other  advances,  was  the  result  of 
accident,  which  arose  from  a  series  of  experiments  carried  on 
for  purely  medical  purposes,  for  confirming  a  theory  that  an 
infusion  of  malt  would  cure  the  sea-scurvy. 

MacBride  for  four  years  kept  the  matter  a  partial  secret,  im- 
parting the  knowledge  to  only  one  firm  of  tanners  in  the  city 
of  Dublin;  but  on  May  31,  1777,  after  being  at  liberty  to  dis- 
close it,  he  did  so  in  a  communication  to  the  Royal  Society,  and 
it  is  recorded  among  the  Philosophical  Transactions. 

Sulphuric  acid  or  vitriol,  as  it  is  also  termed,  is  used  for 
plumping  both  lime  and  sweat  stock.  The  coloring  and  plump- 
ing of  the  latter  are  usually  accomplished  simultaneously  in  the 
handlers,  the  liquor  being  strengthened  after  the  removal  of 
each  pack. 

But  while  vitriol  can  be  employed  without  danger  on  limed 
stock,  it  is  desirable  to  observe  caution  in  employing  it  upon 
sweat  stock  in  order  that  it  may  not  be  too  much  swelled,  as 
its  action  is  more  energetic  upon  hides  which  have  been  sub- 
jected to  the  sweating  process. 

Some  tanners  find  that  it  is  an  improvement  to  treat  sweated 


176 


THE  MANUFACTURE  OF  LEATHER. 


hides  to  a  weak  lime  bath,  especially  when  they  are  to  be 
plumped  by  sulphuric  acid. 

The  acid  is  diluted  with  cold  water,  and  sometimes  more  or 
less  of  the  old  sour  tan  liquors  are  employed  in  conjunction 
with  the  sulphuric  acid,  in  order  to  hasten  the  process  of  pre- 
paring the  hides  for  the  tanning  proper. 

It  is,  of  course,  impossible  to  give  the  exact  proportion  of 
vitriol  to  be  employed  in  every  case ;  but  the  quantity  now 
used  is  about  the  same  as  that  prescribed  by  MacBride,  more 
than  a  century  ago,  viz.,  to  use  his  own  language,  "  a  wine 
pint  of  the  strong  spirit  of  vitriol  is  sufficient  for  fifty  gallons  of 
water  to  prepare  the  souring  at  first;  therefore,  all  you  have 
to  do  in  raising  sole  leather,  is  only  to  prepare  it  beforehand 
in  the  usual  way,  and  when  it  is  fitted  for  the  souring,  mix  up 
a  quantity  of  vitriol  and  water,  according  to  the  number  of 
hides  that  you  require  to  have  raised,  still  observing  the  pro- 
portion of  a  pint  to  fifty  gallons,  which  will  be  enough  if  the 
vitriol  be  of  the  due  degree  of  strength.  The  hides  may  lie  in 
the  souring  till  you  find  them  sufficiently  raised,  for  they  will 
be  in  no  danger  of  rotting,  as  they  would  be  in  the  common 
sourings,  which  in  time  might  turn  putrid  and  rot  the  leather, 
whereas  the  vitriolic  liquid  keeps  off  putrefaction." 

In  the  early  use  of  sulphuric  acid  by  our  tanners,  an  almost 
general  lack  of  knowledge  of  the  nature  and  effect  of  sul- 
phuric acid  under  certain  conditions  was  largely  prevalent,  and 
much  harm  resulted  from  its  injudicious  employment  in  the 
handlers ;  but  while  practical  experience  has  done  much  to  aid 
the  tanner  in  obviating  disastrous  results,  there  is  still  much 
desirable  knowledge  regarding  its  use  in  tanning  that  can  re- 
sult only  from  chemical  experiments. 

The  most  concentrated  sulphuric  acid  is  a  definite  combina- 
tion of  forty  parts  sulphuric  oxide  and  nine  parts  of  water,  the 
formulas  representing  it  being  H.,0,  SO;j,  or  H2S04,  and  it  is  a 
colorless  oily  liquid  having  a  specific  gravity  of  about  1.85,  of 
intensely  acid  taste  and  reaction. 

Oil  of  vitriol  has  a  most  energetic  attraction  for  water,  it 


HANDLING  AND  PLUMPING. 


177 


withdraws  aqueous  vapor  from  the  air,  and  when  it  is  diluted 
with  water  great  heat  is  evolved,  so  that  the  mixture  requires 
to  be  made  with  caution. 

The  atmosphere  is  invariably  charged  with  moisture,  some- 
times to  the  point  of  extreme  dampness  and  complete  satura- 
tion, while  at  other  times  it  is  considerably  above  the  point  of 
saturation.  Any  raw  material,  therefore,  which  is  exposed  to 
the  atmosphere  absorbs  to  a  greater  or  less  degree  a  certain 
quantity  of  water.  Some  chemicals  absorb  a  large  percentage 
and  are  on  this  account  called  hygroscopic. 

For  example,  ordinary  sulphuric  acid  or  oil  of  vitriol  has  a 
great  affinity  for  water,  and  a  glass  half  full  of  acid,  will,  if 
exposed,  gradually  fill  up  and  overflow  with  water,  added  by 
the  mere  attraction  of  moisture  from  the  atmosphere.  Sul- 
phuric acid  is  an  extremely  hygroscopic  substance,  the  mois- 
ture absorbed  being  considerably  over  100  per  cent. 

The  specific  gravity  of  sulphuric  acid  being  so  much  greater 
than  tan-liquor,  it  has  at  all  times  a  strong  tendency  to  settle 
and  mark  with  spots  of  different  colors  the  grain  of  the  pack, 
and  is  is  only  by  strict  watchfulness  that  this  can  be  avoided, 
and  when  vitriol  is  added  to  the  pack,  it  should  be  done  before 
the  sides  are  thrown  in,  and  the  plunging  should  be  faithfully 
performed  in  order  to  prevent  the  discoloring  of  the  grain  by 
the  settling  of  the  acid.  The  swelling  or  "  plumping"  process 
is,  for  the  reasons  previously  stated,  accelerated,  and  the  falling 
back  of  the  hides  into  their  previous  state  prevented  by  the  use 
of  hard  water. 

PLUMPING  BY  MEANS  OF  ACETIC  ACID. 

The  most  experienced  tanners  do  not  consider  the  use  of 
acetic  acid  as  advantageous  for  swelling  sole  leather.  While  it 
is  admitted  that  the  acid  will  make  the  cellular  substance  of 
the  hide  absorb  water  and  thus  swell,  and  will  also  prepare  the 
gelatines  of  the  hide  for  the  further  processes  of  tanning,  but 
the  acid  will  destroy  the  albumen  and  the  albumen  cells  of  the 
hide.    For  this  reason,  hides  tanned  in  old  acid  liquors  are 


178 


THE  MANUFACTURE  OF  LEATHER. 


always  weaker,  soft  and  spongy.  Mineral  acids  are  still  more 
destructive,  as  they  coagulate  the  albumen  of  the  hide  and  give 
it  a  brittleness,  while  they  also  attack  other  constituents  of  the 
hide  and  prevent  the  natural  fermentation  of  the  liquors.  If 
sole  leathers  in  the  first  liquors  are  swelled  by  the  use  of  min- 
eral acids,  the  albumens  cannot  come  to  the  surface  of  the  hide. 
The  gelatines  will  be  dissolved,  but  according  to  the  strength 
of  acid  used  will  be  more  or  less  decomposed,  and  the  result 
will  be  that  the  finished  leather  will  look  bad  as  to  color,  but 
will  be  hard  and  liable  to  crack.  Fir  tannins  are  supposed  to 
contain  more  acid-swelling  properties  than  either  mineral  or 
acetic  acid,  and  German  tanners  add  it  to  their  liquors  and 
allow  it  to  ferment  for  this  purpose.  This  is  considered  the 
only  proper  means  of  swelling  hides  without  injury  to  the 
cellular  tissues  or  the  destruction  or  displacement  of  the  al- 
bumen of  the  hide.  Lactic  acid  is  a  good  agent  for  plumping 
hides — the  only  objection  to  it  being  its  present  high  cost. 


CHAPTER  XI. 


LAYING-AWAY. 

THE  hides  having  been  raised,  the  texture  dilated,  and  there- 
fore weakened,  and  being  deprived  of  that  natural  gum  which 
absorbs  moisture,  are  in  a  condition  to  be  tanned,  that  is  to 
have  their  fibres  strengthened  and  re-united. 

Tannin  is,  therefore,  an  astringent  and  impregnating  substance, 
by  the  ageney  of  which  the  fibres  maintain  their  independence 
and  the  faculty,  as  it  were,  of  sliding  one  upon  another  in  their 
moist  state,  and  by  the  means  of  which,  also,  the  dried  leather 
is  rendered  manageable  and  elastic. 

Without  tannin  the  skin  becomes  horny  as  it  dries,  and  loses 
all  elasticity  and  malleability,  which  is  due  to  the  fact  that  the 
bunches  of  interwoven  and  compact  fibrous  cellular  tissue,  of 
which  it  is  composed,  stick  together,  and  constitute  then  a  con- 
tinuous, semi-transparent  mass. 

Leather  is  probably  not,  as  has  been  heretofore  considered,  a 
chemical  combination  of  the  animal  substance  with  the  tanning 
substance;  for  the  reason  that  the  latter*  is  never  absorbed  in 
equal  proportions,  but  in  variable  quantities,  according  to  the 
concentration  of  the  liquid  and  the  nature  of  the  dissolvent. 
"  One  may  even  obtain  leather  by  the  sole  use  of  fatty  sub- 
stances, for  which  there  can  be  no  question  of  a  chemical  com- 
bination with  the  animal  tissue.  Mr.  Knapp  has  even  suc- 
ceeded in  tanning  or  making  leather  without  tanning  elements. 

*  Some  chemists  object  to  this  paragraph,  one  writing  as  follows:  "  It  cannot  be 
said  that  for  the  reason  the  tanning  substance  is  never  absorbed,  etc.,  because  a  piece 
of  leather  which  is  thoroughly  tanned,  when  shredded  and  treated  with  petroleum 
naphtha  to  remove  fat,  oil  and  water,  and  to  thoroughly  remove  all  soluble  matter, 
such  as  tannin  and  non-tannins,  always  contains  about  the  same  amount  of  hide 
substance  and  tanning  substance  after  deducting  the  mineral  matter  or  ash." 

(  179  ) 


i8o 


THE  MANUFACTURE  OF  LEATHER. 


Starting  from  this  principle  that  the  filaments  adhere  or  stick 
together  only  when  they  are  swollen  by  water,  he  has  put  the 
hide  in  contact  with  such  a  liquid  as  alcohol  or  ether,  which, 
expelling  the  water  by  endosmosis,  deprives  the  fibres  of  their 
faculty  of  sticking.  He  has  obtained  in  this  way  a  tawed  skin, 
of  a  nice  white  color,  and  having  all  the  physical  qualities  of 
tawed  hides.  The  same  result  is  obtained  by  suspending  a 
cleansed  skin  in  anhydrous  ether  placed  above  a  layer  of  chlor- 
ide of  calcium.  The  water  with  which  it  is  impregnated  diffuses 
itself  in  the  ether  and  is  gradually  absorbed  by  the  chloride  of 
calcium.  Any  leather  thus  prepared — the  only  difference  in 
which  from  the  moist  hide,  dried  and  horny,  consists  in  the 
physical  state  of  the  fibres,  which  have  kept  their  independence 
— becomes  an  ordinary  skin,  with  all  its  qualities,  as  soon  as  it 
is  moistened. 

"  It  results  from  these  interesting  experiments  that  tanning  is 
based  rather  on  a  physical  action  than  on  a  chemical  reaction. 
The  tanning  substances,  penetrating  the  hide  by  endosmosis, 
envelop  the  fibres,  adhere  on  their  surface  through  an  attrac- 
tion similar  to  that  which  causes  the  precipitation  of  coloring 
matters  on  the  surface  of  textile  fibres.  The  fibres  thus  sur- 
rounded by  a  layer  of  foreign  matter  do  not  adhere  any  more 
in  drying. 

"  The  faculty  which  the  tanning  substances  possess  besides, 
of  rendering  the  leather  imputrescible,  is  independent  of  their 
physical  action.  It  may  disclose  itself  more  or  less  energeti- 
cally, according  to  the  more  or  less  antiseptic  nature  of  the 
compound  used. 

"  A  very  interesting  experiment  of  Knapp  shows  besides  that 
one  may  compare  the  leathers,  as  regards  the  solidity  of  the 
tanning  with  dyed  tissues,  some  of  which  are  of  good  tint  and 
others  of  false  tint. 

"Thus  the  hides  tanned  with  tan-bark  resist  the  action  of 
water,  while  those  prepared  with  the  tannin  of  the  gall-nut 
come  back  to  the  state  of  untanned  hide,  after  a  prolonged 
wash  with  carbonate  of  soda,  which  proves  that  the  active 


LAYING- AW  AY. 


1 8  r 


substance  of  tan  is  not  entirely  identical  with  gallotannic 
acid."* 

Following  this  theoretic  discussion  we  shall  now  proceed 
with  the  final  step  in  the  process  of  tanning  heavy  hides  and 
skins,  such  as  are  employed  for  sole  and  upper  leathers,  etc., 
which  is  the  laying  away  of  the  stock.  The  usual  size  of  the 
lay-away  vats  for  sole  leather  hides  is  nine  feet  long,  seven  feet 
wide  and  eight  feet  deep,  and  in  these  the  stock  is  usually 
placed  with  the  grain  side  up  in  order  to  avoid  "  hook  marks  " 
in  removing  them. 

The  stock  is  laid  away  by  being  spread  out  smoothly  and 
upon  the  bottom  of  the  tanvat,  and  between  each  layer  there 
is  sprinkled  a  slight  thickness  of  ground  bark  until  the  vat  is 
filled  by  the  stock  and  bark  thus  laid  in  stratum  super  stratum. 

Tan-liquor  is  then  run  into  the  vat,  and  when  the  interstices 
are  filled  the  whole  is  crowned  with  a  layer  of  bark  which  tan- 
ners call  a  "heading." 

Formerly  the  inter-laying  layers  of  bark  were  depended  upon 
to  do  the  tanning;  but  at  the  present  time  in  this  country  the 
bark-liquor  is  relied  upon  and  not  the  inter-laying  bark. 

The  bark  ought  not  to  be  shaved  too  fine  for  the  lay-aways. 
This  is  important  where  whole  hides  are  tanned.  It  is  not  so 
important  where  sides  are  tanned.  If  the  bark  is  too  fine,  it 
excludes  the  liquor  from  circulation  between  the  hides,  and 
they  do  not  come  out  of  the  lay-aways  fully  tanned. 

In  the  early  stages  the  green  stock  requires  more  attention 
than  when  it  is  nearly  tanned,  as  at  first  it  absorbs  the  tannin 
very  rapidly  and  then  gradually  its  capacity  for  absorption 
grows  less  until  at  the  finish  it  refuses  further  to  imbibe  the 
tannic  acid.  The  skins  do  not  absorb  an  unlimited  quantity  of 
tannin,  and  are  probably  not  improved  by  remaining  a  long 
time  in  the  vat. 

The  number  of  layers  and  the  period  of  each  differ  for  the 
various  leathers,  and  depend  upon  the  substance  and  weight  of 


*  Wurtz.  Dictionnaire  de  Chimie,  Pure  et  Appliquee,  hi.,  193  et  seq. 


1 82 


THE  MANUFACTURE  OF  LEATHER. 


the  stock,  the  strength  of  the  liquors  to  which  it  is  subjected, 
the  season  of  the  year  and  various  other  appendant  matters; 
but  it  is  not  uncommon  in  this  country  to  tan  the  heaviest  sole- 
leather  in  four  layers  of  the  following  periods,  the  liquors  at  the 
end  of  each  stage  being  of  the  indicated  degrees  of  strength, 
which  gradually  increase  from  say  6°  at  the  start,  to  about  300 
at  the  finish  : 


1st  layer,  12  days  .        .        .        .  .15° 

2d       "       18      "  20° 

3d     "     24    "  250 

4th    "     36    "  300 


Making  the  whole  period  ninety  days,  and  in  some  cases  it 
has  been  accomplished  in  much  less  time.    See  Chapter  XXIV. 

In  order  to  obtain  full  weight  and  brighter  color  the  time  of 
the  final  layer  is  prolonged,  for  when  insufficient  time  is  allowed 
to  this  layer  there  will  be  lack  of  solidity  and  the  grains  will  be 
inferior. 

In  the  manufacture  of  finer  grades,  such  as  oak-tanned 
sole-leather  of  the  kind  which  is  used  for  the  soles  of  ladies'  and 
children's  shoes,  the  packs  are  generally  laid  away  five  times. 
New  liquors,  or  mixtures  of  new  and  old,  are  preferable  for  dry 
hides,  old  liquors  for  slaughtered.  When  laid-away  in  bark 
the  packs  are  changed,  as  has  been  stated,  until  tanned.  Much 
care  and  judgment  are  necessary  in  proportioning  the  continu- 
ally increasing  strength  of  the  liquors  to  the  requirements  of 
the  leather  in  the  different  stages  of  the  process.  The  liquors 
should  also  be  kept  as  cool  as  possible,  within  certain  limits, 
and  ought  never  to  exceed  a  temperature  of  8o°  F.  Too  high 
a  heat,  with  a  liquor  strongly  charged  with  the  tanning  princi- 
ple, is  injurious  to  the  life  and  color  of  the  leather,  and  the  use 
of  a  too  weak  one  must  also  be  avoided.  Hides  treated  with 
liquors  below  the  proper  strength  become  relaxed  in  their  tex- 
ture and  lose  a  portion  of  their  gelatine.  The  leather  loses  in 
weight,  and  is  much  more  porous.    The  greatest  strength  of 


LAYING- A  WAV 


183 


liquor  used  for  handling  should  not  exceed  160  by  the  barko- 
meter:  and  that  employed  in  laying-away  should  mark  at  its 
greatest  strength  from  30  to  350. 

It  is  the  custom,  when  the  liquors  in  the  lay-away  vats  are 
gradually  increased  in  strength,  to  remove  the  packs  after  the 
stock  has  laid-away  long  enough,  and  run  the  ooze  through 
wooden  pipes  into  a  receiver,  and  from  thence  to  pump  the 
liquor  back  to  the  leaches,  where  it  passes  through  the  bark  and 
is  restrengthened,  and  then  run  as  new  liquor  into  the  vats. 

Another  methed  is  to  allow  the  fresh  and  strongest  liquor 
direct  from  the  leaches  to  pass  first  upon  the  head  packs  of  the 
last  layer,  and  from  thence  to  the  next,  and  so  on  through  all 
the  layers,  and  of  course  decreasing  in  strength  and  .becoming 
more  acid  until  it  finally  passes  upon  the  first  lay-aways,  or 
into  the  handlers,  where  it  is  exhausted. 

\\  hen  this  method  is  employed  the  liquors  when  they  come 
from  the  leaches  should  be  at  least  300  and  ought  not  to  exceed 
35°  in  strength;  but  the  liquor  should  never  in  the  end  be 
allowed  to  remain  upon  the  stock  after  the  strength  is  spent. 

When  heat  is  used  on  the  head  leaches  the  liquor  sometimes 
enters  the  lay-away  yard  in  a  hot  condition,  and  the  intent  is  of 
course  to  turn  it  into  the  head  lay-away;  but  sometimes  the 
attendant  by  mistake  allows  it  to  run  on  the  green  stock,  thereby 
causing  damage  to  the  leather,  as  the  "  black  rot"  will  be  cer- 
tain to  set  in  to  greater  or  less  extent,  especially  in  the  heated 
season  of  the  year. 

Fig.  38. 


The  jack  shown  in  Fig.  38  is  used  for  raising  whole  hides  up 
in  the  lay-away  vats  so  that  the  men  can  take  hold  of  them. 


THE  MANUFACTURE  OF  LEATHER. 


When  the  whole  hides  are  laid  away,  they  are  placed  upon  a 
float  made  by  floating  two  sticks  about  two  inches  square  length- 
wise of  the  vat  on  top  of  the  liquor,  and  then  lowering  a  piece 
of  timber  4x6  inches  so  that  it  will  be  in  the  centre  of  the  vat 
at  right  angles  to  the  length.  This  timber  has  a  hole  through 
each  end,  through  which  passes  a  rope  which  is  long  enough 
to  extend  about  two  feet  above  the  top  of  the  vat.  Two  short 
sticks  are  then  laid  across  the  two  long  sticks  near  the  ends, 
and  the  hides  are  then  laid  away  in  the  usual  manner. 

As  laying  away  continues,  the  float  sinks.  When  the  time 
comes  to  raise  the  hides,  a  jack  is  placed  alongside  the  vat  and 
the  end  of  the  rope  wrapped  around  the  hook  on  the  end  of 
the  jack,  and  the  hides  are  gradually  lifted  to  the  full  extent  of 
the  jack,  and  the  rope  is  wrapped  around  a  movable  peg,  which 
is  placed  in  a  hole  1  l/2  inches  from  the  edge  of  the  vat  in  the 
alley  or  partition  which  separates  the  vats.  Then  the  jack  is 
carried  to  the  opposite  side  of  the  vat,  where  the  operation  is 
repeated. 

In  tanning  heavy  upper  leather  the  practice  among  some  of 
our  best  tanners  is  to  first  handle  the  sides  on  sticks  for  ten  or 
twelve  days,  and  then  lay  them  away  twice  in  bark,  both  lay- 
aways  generally  extending  over  a  period  of  about  sixty  days, 
the  first  lay-away  being  for  about  twelve  days  and  the  second 
for  about  forty-eight  days.  After  this  the  sides  are  split  and 
then,  after  being  leveled  off,  the  sides,  twenty-five  at  one  time, 
are  placed  in  a  large  revolving  wheel  and  worked  for  about  ten 
minutes  with  moderately  strong  gambier  liquor.  From  thence 
the  sides  go  again  into  the  handlers,  but  this  time  without 
sticks,  and  are  drawn  each  day  for  about  fifteen  days.  This 
completes  the  tanning  of  the  upper  leather,  and  it  is  then  ready 
for  the  scouring  and  finishing. 

Light  upper  leather,  such  as  grain  and  splits,  is  not  laid  away. 


CHAPTER  XII. 


STONING. 

PREVIOUS  to  splitting,  leather  is  usually  "stoned  out"  to 
remove  the  wrinkles  in  the  sides.  This  is  best  done  with  a 
stoning  jack. 

Fig-  39  shows  the  stoning  jack  made  by  J.  T.  Freeman  & 
Co.,  Woburn,  Mass.,  and  it  is  one  of  the  best  machines  made 
for  the  purpose. 


Fit;.  39- 


STONING  JACK. 


This  is  a  very  strong  jack,  and  is  especially  constructed  for 
stoning  out  rough  leather  preparatory  to  splitting.  It  will 
stand  a  very  heavy  pressure  and  is  just  the  machine  to  take 
out  the  wrinkle  in  rough  harness  or  belt  leather,  etc. 

The  Vaughn  machine  shown  in  Chapter  XVI  is  also  invalu- 
able for  stoning  out  previous  to  splitting. 

(185) 


CHAPTER  XIII. 


SPLITTING  LEATHER. 

After  the  sides  have  been  removed  from  the  handler  vats 
they  are — in  the  manufacture  of  upper  leather  and  some  other 
varieties  of  leather — hung  on  poles  in  the  yard  of  the  tannery 
to  harden,  or  pressed  in  a  power  press  sufficiently  dry  for  the 
splitting  machine,  and  then  carried  to  the  cellar  preparatory  to 
being  split.  For  other  and  more  minute  details  in  relation  to 
splitting  leather  the  reader  is  referred  to  the  chapters  treating 
of  the  manufacture  of  grain  and  split  leathers. 

Fig.  40  shows  an  interior  peispective  view  of  the  cellar  of  an 
upper-leather  tannery.  Piles  of  sides  that  have  been  dam- 
pened, and  in  condition  to  be  split  are  shown  at  1  and  4.  The 
three  splitting  machines  in  a  line,  marked  2,  are  known  as  the 
Union  Splitting  Machines;  the  one  in  the  background  marked 
3,  is  the  Belt-Knife  Machine.  The  manner  in  which  power  is 
supplied  to  the  machines  by  means  of  a  line-shaft  is  shown,  the 
line-shaft  being  marked  5. 

For  those  who  are  building  or  equipping  tanneries,  views  of 
this  kind  contain  many  valuable  suggestions,  as  those  in  this 
work  were  taken  under  the  author's  personal  supervision  from 
some  of  the  most  modern  and  concededly  the  best  arranged 
tanneries  in  the  United  States. 

SPLITTING  MACHINES. 

Early  in  1831  Alpha  Richardson,  of  Boston,  Mass.,  patented 
his  first  splitting  machine  for  leather. 

Seth  Boyden,  of  Newark,  N.  J.,  had  nearly  a  quarter  of  a 
century  previous  to  this  invented  a  machine  for  this  purpose; 
but  while  a  large  number  of  machines  of  this  character  had 

(186) 


1 88 


THE  MANUFACTURE  OF  LEATHER. 


come  into  use,  there  were  numerous  objections  to  them  which 
it  remained  for  Richardson  to  overcome. 

He  gave  great  attention  to  the  perfection  of  his  contrivance, 
and  continued  to  improve  it  until  1856,  when  he  combined  all 
his  patents  in  the  "  Union  Splitting  Machine." 

Since  the  successful  introduction  of  splitting  machines  hides 
have  been  split  to  meet  all  required  conditions,  and  they  may 
be  split  either  in  a  green  or  tanned  state. 

In  the  manufacture  of  heavy  upper  leather  the  sides  are  split 
after  being  only  partially  tanned. 

When  it  is  desired  to  split  whole  hides,  as  in  the  manufacture 
of  enameled  leather  for  carriage  tops,  etc.,  a  machine  con- 
structed on  a  different  principle  is  employed.  The  one  in  most 
common  use  for  this  purpose  is  known  as  the  "  Belt-Knife 
Splitting  Machine,"  which  was  invented  in  1854  by  Joseph  F. 
Flanders  and  Jere  A.  Marden  of  Newburyport,  Mass.,  and 
which  machine  is  now  manufactured  by  The  American  Tool 
and  Machine  Co.,  Boston,  Mass.  The  Belt-knife  Machine  has 
almost  driven  the  Union  Splitting  Machine  out  of  the  eastern 
currying  shops,  but  the  latter  machine  is  still  employed  in  the 
western  states. 

The  facilities  afforded  by  machines  of  the  character  that  have 
been  mentioned,  allow  good  "grain  splits"  to  be  obtained, 
which  are  used  very  largely  for  shoes,  and  also  for  harness, 
trunks,  etc.,  and  the  large  production  of  buffed  and  grain 
leathers,  which  are  now  so  much  used  in  this  country,  and  form 
an  important  item  in  our  export  list,  has  been  greatly  aided  by 
them. 

Fig.  41  shows  a  perspective  view  of  the  Union  Splitting 
Machine,  geared  so  as  to  be  run  by  steam  power. 

Fig.  42  shows  a  perspective  view  of  an  attachment  patented 
in  1883  by  John  A.  Enos,  to  prevent  injury  to  the  arms  of  those 
who  operate  the  ordinary  splitting  machines  of  the  character 
which  have  been  described  above. 

As  generally  practiced  in  the  factories  where  leather-splitting 
is  carried  on  largely,  the  leather  is  held  pressed  against  and 


SPLITTING  LEATHER. 


wrapped  around  the  drawing-roller  by  the  hands  of  the  opera- 
tor, who  is  in  great  danger  of  being  caught  and  having  his  arms 
broken,  such  accidents  being  of  very  frequent  occurrence. 


Fig.  41. 


Machines  have  also  been  made  in  which  the  leather  has  been 
drawn  or  fed  against  the  edge  of  the  knife  or  cutter  by  a  pair 


Fig.  42. 


of  cylindrical  rolls  which  act  upon  the  opposite  surfaces  of  the 
leather,  pinching  it  between  them  ;  but  when  a  stationary  knife 


THE  MANUFACTURE  OP'  LEATHER. 


or  cutter  is  employed,  it  is  claimed  that  it  has  been  found  im- 
practicable to  use  such  a  pair  of  feeding-rollers,  as  their  holding 
power  is  not  sufficient  to  draw  the  leather  uniformly  against 
the  edge  of  the  cutter.  Enos  discovered  that  by  fluting  or 
corrugating  the  surfaces  of  the  drawing  or  feeding  rollers,  and 
preferably  also  gearing  them  together,  so  that  the  projections 
or  convex  portions  of  one  roller  will  fall  within  the  recesses  or 
concave  portions  of  the  other  roller,  it  is  possible  to  obtain  suf- 
ficient holding  power  upon  the  leather  to  draw  it  properly 
against  the  edge  of  the  knife  and  split  the  leather. 

Enos's  invention  is  shown  in  detail  in  Figs.  43  to  45,  and 
consists,  essentially,  in  the  combination,  with  the  usual  splitting 
knife  and  parts  co-operating  therewith,  to  present  the  leather 
properly  to  its  edge,  of  a  fluted  or  corrugated  drawing  roller 
and  a  corrugated  or  fluted  auxiliary  or  gripping  roller,  and 
mechanism  by  which  the  operator  can  force  the  rollers  against 
the  leather  between  them. 

In  the  present  embodiment  of  this  invention  the  gripping 
roller  is  mounted  in  bearings  upon  pivoted  arms,  which  are 
acted  upon  by  an  actuating-treadle  to  draw  the  gripping  roller 


Fig.  43. 


X 


toward  the  drawing-roller,  and  the  gripping-roller  is  drawn 
back  or  retracted  by  its  own  weight  or  other  suitable  retractor. 


SPLITTING  LEATHER. 


191 


so  that  the  operator  by  merely  raising  his  foot  can  at  once  re- 
lieve the  pressure  on  the  leather,  which  will  then  cease  to  be 
drawn. 

Fig.  43  is  a  front  elevation  of  a  leather-splitting  machine 
embodying  Enos's  invention  ;  Fig.  44  an  end  elevation  thereof; 
and  Fig.  45  a  vertical  section  on  line  x  x,  Fig.  43. 

The  framework  a,  knife  b,  and  mechanism  for  presenting  the 
leather  to  be  split  to  the  knife-edge,  may  all  be  of  any  usual 


Fig.  44-  FlG-  45- 


construction,  these  parts  not  constituting  the  present  invention. 
The  leather  presented  to  the  knife  at  a  short  distance  from  the 
end  of  the  piece  or  side  has  its  end  carried  over  the  corrugated 
or  fluted  drawing-roller  e,  mounted  on  a  shaft /,  shown  as  actu- 
ated by  a  gear,  g,  meshing  with  a  pinion,  h,  on  a  shaft,  z,  hav- 
ing the  usual  fast  and  loose  pulleys  for  the  driving-belt.  Thus 
by  wrapping  the  leather  around  the  roller  e,  or  pressing  it 
against  the  surface  thereof,  the  leather  will  be  drawn  against 
the  edge  of  the  knife  and  split  by  the  power  by  which  the 
roller  is  rotated,  although  it  is  necessary,  in  addition  to  the 
power,  to  provide  means  for  holding  the  leather  upon  the  sur- 
face of  the  drawing-roller.  This  is  accomplished  in  accord- 
ance with  the  present  invention  by  the  auxiliary  or  gripping 
roller  m,  having  its  bearings  in  carrying-arms  n,  pivoted  on  the 


THE  MANUFACTURE  OF  LEATHER. 


shaft  o,  so  that  the  roller  can  be  swung  or  oscillated  upon  the 
arms  toward  and  from  the  roller  c.  The  arms  n  have  exten- 
sions forming  therewith  a  bent  actuating-lever  for  moving 
the  roller  m  toward  the  roller  e,  the  extensions  or  arms  being 
provided  with  counter-balance  weights,  w,  for  partly  balancing 
the  weight  of  the  roller  m.  The  arms  n'  are  connected  by  links 
or  rods  p  with  the  actuating-treadle  r,  so  that  the  operator,  by 
depressing  the  treadle,  forces  the  roller  m  toward  the  roller  c  to 
grip  the  leather  between  them.  The  roller  m  is  corrugated  or 
fluted  to  correspond  with  the  roller  e,  as  shown  in  Fig.  45,  and 
the  roller  e  is  provided  at  one  end  with  a  gear,  s,  meshing  with 
an  intermediate  /,  that  meshes  with  a  pinion,  f,  fixed  upon  the 
shaft  0,  which  has  at  its  other  end  a  pinion,  //,  meshing  with  a 
gear  u',  connected  with  the  roller  m.  The  gears  s  and  u'  are  of 
the  same  size,  and  the  pinion  t  t"  u  are  of  uniform  size,  so  that 
the  rollers  m  and  c  rotate  in  unison  in  opposite  directions  and 
the  projections  of  the  one  roller  fall  into  the  recesses  of  the 
other.  The  two  rollers  thus  co-operate  to  grip  and  draw  the 
leather,  which  passes  down  between  the  rollers  instead  of  being 
wrapped  around  one  roller,  as  in  the  machines  heretofore  em- 
ployed. By  the  employment,  in  connection  with  a  fluted 
drawing-roller  actuated  by  power  in  the  usual  manner,  of  a 
corresponding  fluted  auxiliary  roller — or,  in  other  words,  a 
co-operating  pair  of  fluting,  gripping,  and  drawing  rollers — the 
danger  to  the  operator,  it  is  claimed,  is  removed,  and  the  oper- 
ation and  capacity  of  the  machine  for  splitting  the  leather  are 
improved  and  increased. 

In  the  old  machines  employing  but  a  single  roller,  the 
leather,  when  wrapped  around  it,  frequently  forms  bunches, 
causing  inequality  in  the  tension  of  the  leather,  and  consequent 
inequality  in  the  thickness  of  the  split  material. 

Frequently  difficulty  in  splitting  is  traced  to  simple  causes, 
which  are  easily  remedied.  Sometimes  the  hides  are  not 
properly  soaked,  and  at  others  the  machine  is  not  correctly 
adjusted.  The  leather  should  be  soaked  just  enough  to  allow 
the  water  to  penetrate  the  hide,  and  no  more.    After  that  it 


SPLITTING  LEATHER. 


193 


should  be  allowed  to  mellow,  which  should  be  from  twelve  to 
twenty-four  hours.  Care  should  be  taken  to  cover  the  edges 
with  wet  cloths  or  splits,  and  to  put  them  in  a  clean  place 
where  they  will  not  get  grit.  In  most  cases  it  will  be  found 
advantageous  to  soak  them  in  warm  water. 

With  the  Union  Splitting  Machine  the  following  hints  may 
prove  valuable :  Before  putting  in  the  leather  to  split,  turn  the 
beam  roller  over  on  to  the  knife,  and  see  if  the  center  of  the 
roller  sits  exactly  over  the  edge  of  the  spring  plate,  and,  if  it 
does  not,  adjust  it  by  moving  the  two  screws,  one  on  each  side 
in  front  of  the  gauge  box  ;  next  see  that  the  edge  of  the  knife  is 
slightly  below  the  spring  plate,  and  about  the  distance  of  a  cent 
piece  away ;  see  that  the  spring  plate  is  gauged  exactly  true 
along  the  edge.  To  prove  this,  place  the  coin  on  the  face  of  the 
knife,  and  close  up  to  the  spring  plate  ;  run  the  coin  across  from 
one  side  to  the  other,  and,  if  the  plate  is  not  perfectly  even  and 
square  with  the  edge  of  the  coin  all  across,  regulate  the  same 
with  the  long  spanner  by  moving  the  screws  underneath  ;  if  the 
spring  plate  is  not  set  perfectly  true,  unevenness  of  substance 
will  be  the  result.  In  gauging,  first  try  the  machine  on  a  split, 
so  that  little  damage  will  be  done  if  the  exact  distance  is  not 
obtained  the  first  try,  also  see  that  the  spring  plate  sits  evenly  on 
the  screws  all  along  ;  otherwise,  regulate  with  the  eye  bolts  that 
are  underneath.  To  ascertain  if  the  plate  sits  on  the  screws, 
strike  the  plate  lightly  with  a  hammer  over  the  screws,  and  it 
will  be  noticed  if  the  plate  springs  or  not ;  allow  the  plates  to  be 
sprung  slightly  hollow  from  back  to  front.  An  important  point 
to  be  observed  is  the  proper  sharpening  of  the  knife.  It  is 
almost  an  impossibility  to  keep  a  knife  true  and  the  edges  in 
good  condition  by  hand  sharpening.  Care  should  be  taken  to 
clear  the  edges,  and  for  this  purpose  Scotch  or  Tarn  O'Shanter 
stones  are  considered  the  best.  After  properly  fixing  the  knife, 
place  the  leather  across  with  the  belly  part  towards  the  outside, 
and  bring  down  the  roller,  taking  care  that  the  same  is  properly 
pressed  home  with  the  lever  before  starting  the  machine. 
When  splitting  whole  sides,  assist  the  belly  part  through  as 

*3 


194 


THE  MANUFACTURE  OF  LEATHER. 


much  as  possible  by  pulling  at  the  edge;  otherwise,  the  belly 
being  longer  than  the  straight  edge,  the  surplus  will  be  worked 
back  and  puckered  up,  cutting  it  in  holes.  If  the  sides  are  in- 
clined to  be  baggy  or  pouchy,  take  the  wood  from  the  lip  roller 
and  place  one  hand  opposite  the  bag  or  pouch,  and  work  the 
machine  until  the  pucker  is  drawn  out;  then  again  place  the 
wood  in  lip  roller  and  finish  the  side.  When  placing  the  hands 
on  the  roller  to  draw  out  a  pouch,  particular  care  must  be 
taken  not  to  allow  the  hands  to  get  too  far  underneath  round 
the  roller,  as  the  fingers  are  apt  to  be  trapped  with  the  leather, 
and  the  arm  broken  or  pulled  out,  which  has  happened  on 
several  occasions. 

THE  BELT  KNIFE  LEATHER  SPLITTING  MACHINE. 

The  American  Tool  and  Machine  Co.,  of  Boston,  are  the 
original  manufacturers  of  the  belt  knife  Splitting  Machine 
shown  in  Fig.  46,  having  been  manufacturing  them  for  the  last 
thirty  years. 

The  original  machine  was  developed  after  the  expenditure  of 
large  sums  of  money  and  valuable  time,  and  has  been  steadily 
improved  during  the  past  twenty  years,  particular  attention 
having  been  paid  to  alterations  and  changes  in  the  machine 
during  the  last  three  years.  Their  most  recent  machine  is 
shown  in  the  illustration. 

In  view  of  the  fact  that  the  first  machines  were  built  to  run  at 
a  speed  of  about  1 50  revolutions  per  minute,  its  speed  has 
gradually  increased  until  now  some  of  the  machines  are  run  at 
as  high  a  rate  of  speed  as  425  revolutions.  This  high  speed  is 
admissible  on  some  kinds  of  leather,  but  for  the  general  split- 
ting work  the  builders  recommend  a  speed  of  from  300  to  350 
per  minute. 

The  necessity  and  anxiety  to  do  work  and  do  it  quickly,  in 
order  to  reduce  the  cost  of  production,  were  not  provided  for  in 
all  cases,  and  the  machines  were  not  strengthened  and  re- 
modeled to  meet  the  high  speeds  and  the  most  severe  work 
demanded  by  the  leather  manufacturers  until  within  the  last 


SPLITTING  LEATHER. 


195 


three  years.  Since  then  the  builders  have  been  making  con- 
stant improvements  and  the  machine  has  been  practically  re- 
modeled, having  been  made  much  heavier  in  all  parts  that  past 
experience  had  proven  required  strengthening,  and  the  quality 
of  the  material  of  which  the  machine  is  made  received  special 
consideration,  so  that  to-day  they  are  turning  out  a  machine 
that  is  made  of  the  materials  best  suited  to  withstand  the  severe 
duties  demanded. 

This  point  was  one  that  required  long  and  careful  experi- 
menting to  determine  which  material  was  best  suited  for  the 
service.  In  many  cases  seemingly  unimportant  parts  of  the 
machine  required  the  most  care  and  experiment  before  the  most 
satisfactory  material  to  use  could  be  determined  on. 

The  high  speeds  of  the  present  day  require  a  massive  con- 
struction and  strength  to  reduce  the  vibration  and  strains,  and 
it  was  found  that  the  ordinary  materials  that  could  be  pur- 
chased from  stock  were  unsuited,  and  the  American  Tool  and 
Machine  Co.  were  therefore  obliged  to  have  special  steel  manu- 
factured to  suit  the  purpose. 

The  latest  machines  that  have  been  put  into  the  manufac- 
turers' hands,  and  run  by  experienced  men  who  have  used  these 
machines  for  the  past  fifteen  or  twenty  years,  have  been  pro- 
nounced much  better,  and  the  fact  that  the  amount  of  repair 
work  has  been  reduced  nearly  75  per  cent.,  indicates  that  the 
builders  have  a  machine  that  is  economical  and  exceedingly 
durable. 

We  would  mention  among  other  things  that  the  builders  have 
increased  the  weight  of  the  machine  very  materially,  thus  mak- 
ing it  stiffer  and  stronger.  They  have  put  on  gears  that  are 
machine  cut;  the  rolls  and  shafts  are  carefully  turned;  the 
screws  are  lathe  made  and  are  closely  fitted. 

These  are  small  points,  but  the  fact  that  the  machine,  in 
order  to  do  good  work,  must  be  taken  down  and  cared  for  and 
replaced,  necessitates  that  all  the  screws  and  parts  should  be 
made  of  material  that  will  stand  the  handling  and  the  reassem- 
bling without  getting  out  of  true,  without  the  threads  stretching 
or  the  holes  wearing  unduly. 


When  the  machine  and  parts  are  worn  it  is  difficult  to  do 
close  and  good  work  and  keep  the  knife  properly  adjusted. 


SPLITTING  LEATHER. 


197 


The  position  of  the  knife  and  the  beam  and  its  parts  is  very 
important  to  do  good  work  continually,  and  it  is  necessary  that 
they  maintain  their  adjustment  after  they  are  set,  as  the  splitter 
must  use  up  much  valuable  time  and  delay  on  the  work  by 
continually  stopping  to  adjust  his  machine. 

The  machine  is  not  automatic,  and  to  insure  the  best  work, 
it  does  not  seem  practical  at  this  time  to  manufacture  a  machine 
that  will  automatically  split  leather ;  therefore  to  obtain  the 
highest  standard  of  work,  it  is  necessary  that  a  man  should  have 
experience  in  handling  a  machine  and  must  understand  some- 
thing about  leather  in  order  to  make  a  successful  splitter.  In 
setting  up  the  machine  and  adjusting  it,  and  getting  out  work 
properly,  there  are  many  things  that  will  bother  a  man  who  is 
not  thoroughly  familiar  with  the  machine,  and  it  is  only  by 
careful  study  and  the  closest  observation  that  the  expert  split- 
ters are  able  and  have  been  able  to  attain  the  position  they 
hold.  It  has  been  very  truthfully  said  by  several  of  the  most 
expert,  that  they  have  made  the  machine  a  careful  study,  and 
have  really  made  it  a  life  work. 

These  men  can  split  anything  in  the  shape  of  leather  or 
material  that  can  be  cut  with  a  knife  that  is  required  to  be 
evened  or  divided  into  different  thicknesses.  There  is  no  class 
of  leather  that  is  too  difficult  to  split  on  the  machine  under  the 
careful  handling  of  the  expert  man  ;  leather  in  all  stages  of 
manufacture  from  the  raw  state  to  the  finished  product. 

As  will  be  inferred  from  the  above,  it  is  practically  impossible 
for  a  man  to  learn  the  art  of  splitting  leather  from  any  written 
description  or  written  instruction  that  can  be  given. 

We  might  mention  that  the  belt-knife  splitting  machine  is  in 
successful  operation  for  splitting  pan- cake  and  counter  stock, 
splitting  shoe  linings,  splitting  calf,  goat  and  sheep  skins,  split- 
ting and  skiving  grain  leather,  splitting  book-binding  and  bag- 
stock,  skiving  harness  leather  and  belt  butts,  splitting  felt  for 
hats,  splitting  and  buffing  leather  for  carriage  tops  and  enamel 
leather,  splitting  green  hides  with  hair  on  for  robes  and  coats, 
splitting  hides  or  skins  from  the  lime;  also  celluloid  in  sheets 
and  cow  horns  for  combs. 


198 


THE  MANUFACTURE  OF  LEATHER. 


Referring  to  the  matter  of  grinders,  we  would  say  that  the 
builders  have  been  experimenting  for  some  time  on  a  new 
form  of  conveying  the  power  to  the  grinder  shafts,  and  that 
they  will  soon  have  a  very  simple,  inexpensive  arrangement, 
which  we  trust  will  be  appreciated  by  all  who  use  it. 

It  is  always  necessary  on  high  speed  machinery  to  provide 
a  device  for  stopping  and  starting  the  machinery  readily,  as 
when  a  machine  is  running  at  high  speed  it  is  highly  important 
that  it  should  be  stopped  in  case  anything  should  become  out 
of  order,  before  any  damage  could  be  done  to  it;  for  this 
reason,  the  American  Tool  and  Machine  Co.  have  gotten  out  a 
new  and  improved  patent  friction  pulley  for  the  machine,  by 
means  of  which  it  can  be  started  with  less  power  than  the  ordi- 
nary shifting  belt  requires;  that  is,  the  clutch  that  is  provided 
with  this  pulley,  is  so  constructed  that  the  machine  can  be 
gradually  started  and  instantly  stopped. 

IN  REGARD  TO  SPLITTING  LEATHER 

a  few  instructions  may  not  be  amiss. 

Everything  being  ready,  place  the  leather  in  two  piles  behind 
the  machine.  Place  it  so  the  backs,  as  you  pick  it  up,  will 
come  against  the  head  blocks,  the  flanks  at  the  middle  ;  put  the 
heaviest  at  the  bottom,  the  lightest  at  the  top,  for  as  your  knife 
wears  away  you  are  feeding  larger  leather  which  requires  more 
room,  you  thus  avoid  resetting  the  knife  so  often.  Take  a  side 
of  leather,  grain  up,  the  hind  shank  first,  the  neck  hanging 
down  and  the  back  hanging  straight,  lay  it  upon  the  ring  plate, 
spread  it  as  flat  as  possible,  with  one  hand  push  or  feed  in  the 
projecting  part  of  the  skin,  with  the  other  hand  grasp  the  rib 
on  the  guard  over  the  main  shaft,  holding  thus  the  leather  from 
feeding  too  fast.  As  soon  as  it  begins  to  feed  take  the  loose  end 
and  with  the  hand  on  the  ring  plate  spread  or  straighten  the 
side  out  so  as  to  be  sure  not  to  let  the  leather  catch  at  the  two 
sides  before  the  middle  does,  as  otherwise  the  leather  will  not 
spread  evenly,  but  bunch  up  in  the  middle.  When  that  occurs 
you  must  stop  the  machine  and  raise  the  beam  and  draw  it 


SPLITTING  LEATHER. 


199 


back  as  far  as  it  is  bunched  up,  and  turn  down  the  beam  and 
start  again.  Do  not  pull  all  the  leather  out  or  you  may  have 
trouble  in  starting  in  true  again.  When  you  have  the  leather 
well  fed  in,  the  width  of  the  side,  let  it  go,  for  the  less  hindrance 
you  put  upon  the  feeding  the  better  the  results  will  be.  After 
you  have  split  some  twenty-five  or  thirty  sides  examine  the 
knife,  as  the  wheels  are  constantly  grinding  it  away.  You  must 
keep  resetting  it ;  experience  alone  can  tell  you  how  much  to 
keep  the  knife  up  to  or  away  from  the  notch,  but  until  you 
have  had  experience  adopt  one-eighth  of  an  inch  as  a  safe  dis- 
tance ;  or  rather  the  nearer  you  can  come  and  have  a  scrap  of 
leather  feed  straight  through  when  the  machine  is  set,  the  bet- 
ter it  will  be.  If  the  knife  is  too  close  the  leather  will  not 
feed  through,  but  will  be  carried  by  the  knife  along  the  jaw  to 
the  end.  If  you  should,  as  is  done  in  this  country,  skive  the 
leather,  the  operation  is  the  same,  except  you  feed  with  the 
flesh  side  up  to  the  gauge  roll. 

Of  the  various  troubles  which  may  happen,  or  the  failures  to 
do  good  work,  we  can  say  but  little.  The  same  thing  seldom 
happens  twice,  and  there  may  be  more  than  one  cure  for  any 
trouble,  but  as  a  rule,  if  the  machine  is  properly  set,  the  rubber 
roll  straight,  the  rings  all  the  same  size  and  properly  adjusted, 
the  gauge  roll  and  friction  rolls  true  and  straight  and  the  jaw 
in  condition  to  hold  the  knife,  you  must  split  well.  Of  course, 
the  knife  is  to  be  kept  well  ground  ;  you  cannot  split  with  a 
dull  knife,  and  better  wear  out  a  knife  a  few  days  sooner  than 
spoil  your  work.  Be  careful  not  to  get  oil  upon  the  rubber 
roll,  it  will  soften  it  and  in  a  short  time  destroy  it.  When  the 
roll  gets  out  of  true  or  very  rough,  you  must  get  it  ground 
down  ;  be  sure  and  keep  it  straight  and  smooth.  The  gauge 
roll  will  require  turning  off  once  in  a  while  ;  it  gets  small  in  the 
middle.  The  bearings  get  worn  down  small  and  require 
turning  up;  when  this  is  done,  bore  out  the  brass  boxes  and 
bush  them  with  brass.  After  this  is  once  done  you  have  only 
to  put  in  new  bushing  for  a  new  roll,  or  for  any  subsequent 
turning  of  the  old  one.    Once  in  a  while  take  the  brass  rings 


200 


THE  MANUFACTURE  OF  LEATHER. 


off  the  rod  and  put  the  end  ones  in  the  middle,  the  middle 
ones  on  the  end.  When  you  do  this  be  sure  every  ring  is  sep- 
arate and  free  to  move  and  at  the  same  time  comes  up  so  close 
to  the  next  one  that  you  can  just  see  through  them.  By  thus 
changing  them  you  avoid  turning  them  down  so  often ;  by 
keeping  them  close  together  you  do  not  let  them  tip  on  the 
rod  and  make  ring-marks  upon  the  split.  Use  nothing  but  the 
best  oil  to  oil  up  the  machine,  and  see  that  every  part  is  kept 
clean. 

Too  much  care  cannot  be  taken  to  prepare  the  leather  before 
splitting.  The  best  way  is  to  wet  it  thoroughly  and  pack  it  down 
until  it  is  entirely  moistened  through  ;  it  should  retain  water 
enough  so  that  when  you  double  the  leather  together  and 
squeeze  hard  you  extract  a  little  water.  If  too  dry  there  will 
be  spots  in  it  dryer  than  others,  and  such  places  always  split 
differently  from  the  rest.  If  you  cannot  wait  for  it  to  season, 
the  next  best  plan  is  to  mill  the  leather  in  a  hide  mill ;  in  fact 
it  would  be  a  good  plan  to  do  this  anyway.  The  plan  of  tak- 
ing dry  leather,  wetting  it  in  a  tub  and  splitting  at  once  is  bad, 
and  you  cannot  get  good  work  in  this  way.  If  you  skive  the 
leather  it  should  be  jacked  or  stoned  down  to  take  the  wrinkles 
out  of  the  neck.  Do  this  upon  a  stoning  jack  or  stoning  ma- 
chine, such  as  have  already  been  described  in  Chapter  XII ; 
you  will  find  that  you  cannot  spend  too  much  time  in  preparing 
the  leather  to  split,  the  result  being  amply  better  to  pay  for 
the  time. 

As  to  the  amount  of  work,  you  must  begin  slowly  and  ex- 
amine the  work  as  you  go  along,  but  after  a  time  you  will  find 
you  can  make  about  seventy  to  eighty  cuts  an  hour,  or  even 
more  ;  run  the  machine  as  fast  as  it  can  be  fed  well.  A  great 
deal  depends  upon  the  feeder;  no  machine  will  split  well  if  the 
feeder  is  not  able  to  do  the  work  without  continual  stopping  to 
pull  back  or  straighten  the  leather. 

The  machines  are  made  in  four  sizes,  viz.,  fifty-seven  inches 
(57//),  seventy-two  inches  (72"),  eighty-four  inches  (84"),  and 
one  hundred  and  six  inches  (106").  And  can  be  used  to  ad- 
vantage on  both  wet  and  dry  stock. 


SPLITTING  LEATHER. 


20I 


The  American  Tool  and  Machine  Company  manufacture 
belt  knives  of  the  finest  quality  for  their  machines. 

The  Vaughn  Machine  Co.,  Peabody,  Mass.,  are  constantly 
adding  new  features  to  their  business.  Recently  they  have 
fitted  out  a  shop  adjoining  their  factory  for  the  production  of 
belt  knives.  They  have  machinery  for  grinding,  polishing  and 
straightening,  and  a  special  milling  machine  for  cutting  the 


Fit;.  47. 


bassktt's  bklt  knife  splitting  machine. 

ends  before  brazing.  All  these  machines  are  of  their  own  in- 
vention and  in  use  nowhere  but  in  their  shop.  They  claim 
they  are  making  the  best  belt  knives  in  the  country,  and  the 
appearance  of  their  knives  surely  assists  to  sustain  this  claim. 

The  Vaughn  Machine  Company  have  also  become  the  sell- 
ing agents  of  the  belt  knife  splitting  machine,  made  by  the 
American  Tool  and  Machine  Company,  Boston,  Mass. 

Fig.  47  shows  a  recent  improvement  on  grinder  rigging  for 
belt  knife  splitting  machines.    The  grinder  is  so  arranged  as  to 


202 


THE  MANUFACTURE  OF  LEATHER. 


save  all  floor  space,  and  can  be  used  alike  on  machines  made 
by  the  American  Tool  Company,  and  those  made  by  F.  S. 
Bassett  &  Co.,  Woburn,  Mass.,  which  latter  firm  make  and  sell 


the  grinder  rigging;  the  price  is  $50.  F.  S.  Bassett  &  Co. 
also  manufacture  belt  knife  splitting  machines,  of  which  they 
have  sold  a  large  number  to  tanners  and  curriers  not  only  in 


SPLITTING  LEATHER. 


203 


the  United  States,  but  in  France,  Germany  and  England,  and 
which  are  all  giving  complete  satisfaction. 

Bassett  &  Co.  claim  that  their  belt  knife  splitting  machine  is 
the  most  convenient  to  operate  of  any  on  the  market,  and  that 
it  will  leave  the  leather  in  condition  as  good  as  or  better  than 
that  of  any  other  for  the  following  reasons  : 

1.  The  machine  is  strengthened  in  places  which  have  been 
considered  weak  in  machines  built  heretofore,  thereby  making 
it  less  liable  to  vibration. 

2.  The  improvement  in  regard  to  the  removal  of  the  rubber 
roll  shown  in  Fig.  48  is  a  great  convenience  to  the  operator, 
as  in  all  other  machines  the  work  requires  about  five  hours. 
In  this  machine  the  roll  can  be  removed  in  twenty  minutes, 
thereby  saving  half  a  day's  labor,  which  is  quite  essential  when 
a  machine  is  required  to  run  ten  hours  per  day  to  keep  up  with 
the  work. 

3.  The  bevel  gears  running  the  machine  are  absolutely 
noiseless  and  run  perfectly  smooth,  which  is  a  great  improve- 
ment, as  the  gears  used  on  all  other  machines  not  only  make  a 
great  deal  of  noise,  which  is  very  annoying  to  every  person  in 
the  room,  but  also  tends  to  corduroy  the  leather.  The  ham- 
mering of  the  cogs  when  worn  a  little  seems  to  rattle  the  knife 
so  that  in  grinding  the  same  it  is  more  apt  to  leave  an  uneven 
surface,  which  tends  to  corduroy. 

Every  machine  is  guaranteed,  and  competent  men  are  sent 
with  each  if  required. 

Aside  from  the  above  advantages,  the  Bassett  machine  has 
all  of  the  modern  improvements  used  on  other  makes. 

Bassett  &  Co.  also  keep  on  hand  emery  wheels  and  all  dup- 
licate parts  of  the  belt  knife  splitting  machine. 

Robertson's  grinding  adjustment  for  belt  knife  splitting  machines. 

The  invention  shown  in  Figs.  49-52  is  that  of  James  Robert- 
son, of  Woburn,  Mass.,  the  most  expert  splitter  on  the  belt- 
knife  splitting  machine  in  the  United  States.  It  is  in  use  by  a 
large  number  of  the  leading  tanners  in  this  country  and  it  is  a 
valuable  addition  to  the  belt-knife  splitting  machine. 


204 


THE  MANUFACTURE  OF  LEATHER. 


This  is  an  improved  movement  or  adjustment  of  the  belt- 
knife  of  a  leather-splitting  machine,  whereby  opening  of  doors 
or  kneeling  by  the  operator  is  rendered  unnecessary,  uniformity 
produced  in  the  bevels  on  the  opposite  sides  of  the  knife,  and 
economy  attained  in  the  wear  thereof,  all  with  the  effect  of  im- 

Fig.  49. 


r 


proving  the  quality  of  work  produced  by  the  splitting-knife. 
The  invention  consists  in  the  novel  construction  and  arrange- 
ment of  parts  hereinafter  described,  and  illustrated  in  the  ac- 
companying drawings,  in  which — 

Fig.  49  is  a  front  elevation  of  a  portion  of  a  belt-knife 
leather-splitting  machine  with  Robertson's  improved  grinding 
adjustment  applied  thereto.    Fig.  50  is  a  vertical  section  taken 


SPLITTING  LEATHER.  205 

on  line  x,  Fig.  49,  looking  towards  the  grinders.  Fig.  5  1  is  a 
horizontal  section  taken  on  line  y,  Fig.  50.    Fig.  52  is  a  detail 


in  section  of  a  wrench  whereby  separate  hand  adjustment  of 
one  of  the  grinders  may  be  had. 


THE  MANUFACTURE  OF  LEATHER. 


A  represents  a  portion  of  the  frame  of  an  ordinary  belt-knife 
leather-splitting  machine,  and  A'  a  bracket  attached  thereto. 
Secured  to  the  bracket  A'  is  a  vertical  piece  B  from  which  ex- 
tend portions  B'  which  constitute  ways  for  the  horizontal 
movement  of  the  slides  C,  set  one  above  the  other,  as  shown  in 
Figs.  49  and  50. 

D  D  are  carriages  adjustably  secured  to  slides  at  D' ,  Fig.  5  1, 
and  having  an  independent  movement  (not  new  in  this  inven- 
tion) whereby  they  may  be  moved  up  and  down  and  out  of  the 
way,  if  desired,  by  the  hand-wheels  d. 

E  E'  are  shafts  each  having  one  bearing  in  a  carriage  D, 
(the  other  bearing  being  as  usual,  and  not  new).  The  shafts 
are  driven  by  the  pulleys  e  c' ,  and  have  rigidly  secured  to  them 
the  grinding-wheels  F  F'.  The  grinders  F  F  are  set  on  oppo- 
site sides  of  the  cutting-edge  of  the  endless  belt-knife  K,  which 
is  driven  in  the  usual  manner,  and  is  guided  and  supported  by 
the  grinder-jaw  L,  which  contains  a  back-plate  L'  for  the  pur- 
pose of  moving  the  knife  forward  as  it  wears. 

P  is  a  vertical  shaft  having  its  bearings  in  the  frame  of  the 
machine  and  extending  up  to  a  point  convenient  to  the  oper- 
ator, so  that  he  can  rotate  it  by  means  of  the  hand-wheel  P' 
without  stooping.  On  this  shaft  P  are  fixed  two  worms  R  R' 
which  engage,  respectively,  two  gears  5  S'  which  are  fast  to 
screws  V  extending  into  the  recesses  b  in  the  ways  B' .  These 
screws  engage  nuts  W  which  are  secured  to  the  slides  C,  Figs. 
50  and  51.  By*rotating  the  shaft  P,  therefore,  the  screws  V 
are  rotated,  thus  moving  forward  simultaneously  the  slides  C, 
and  hence  the  carriages  D,  which  move  the  grinding-wheels 
F  P  simultaneously  forward  against  the  opposite  sides  of  the 
edge  of  the  belt-knife  K,  sharpening  and  beveling  both  sides 
thereof  at  once  with  absolute  accuracy,  and  of  course  sharpen- 
ing both  sides  absolutely  alike. 

Should  it  be  desired  to  move  forward  one  carriage  and  its 
grinding  wheel  independently  of  the  other,  an  adjusting  wrench 
H,  Fig.  52,  may  be  applied  to  either  of  the  heads  h  of  the 
•.  crews  or  bolts  B,  the  portion  H'  of  said  wrench  being  used  to 
actuate  the  nut  h'  on  said  heads. 


SPLITTING  LEATHER. 


207 


James  Robertson,  who  is  a  practical  currier  of  Woburn, 
Mass.,  also  manufactures  an  appliance  for  regulating  the  dis- 
tance of  the  knife  from  the  centre  line  of  the  belt-knife  splitting 
machine.  This  he  sells  for  $3.  He  also  makes  another  appli- 
ance for  regulating  the  weight  of  leather  to  be  cut  on  the  belt- 
knife  splitting  machines,  which  he  also  sells  at  $3.  These 
appliances  do  away  with  guess-work  in  operating  the  belt-knife 
machine  and  make  the  work  exact. 

He  also  manufactures  a  Leather  Gauge  which  will  tell  in- 
stantly the  weight  of  leather  per  square  foot. 


CHAPTER  XIV. 


SCOURING. 

AFTER  the  leather  has  been  split  it  is  commonly  handled  in 
liquor  for  about  two  weeks,  which  completes  the  tanning  pro- 
cess, and  the  next  operations  to  which  it  is  to  be  subjected  are 
the  drying  and  finishing  for  market. 

Of  course  different  varieties  of  leather  pass  through  different 
modes  of  treatment,  and  while  there  is  but  little  to  be  done  in 
the  finishing  of  sole  leather,  except  the  drying  and  rolling,  there 
is  much  to  be  done  in  finishing  upper  leathers,  Morocco 
leathers,  etc. 

We  shall  therefore  devote  one  chapter  to  each  of  the  subjects 
of  scouring,  stuffing,  blackening  and  polishing  leather,  and  then 
for  other  details  of  special  branches  of  manufacture  and  for 
coloring  and  dyeing  leather,  refer  the  reader  to  the  various 
chapters  treating  of  those  subjects. 

The  tools  used  in  the  hand  method  of  scouring  leather  are 
the  brush,  stone  and  slicker;  the  brush  is  shown  in  Fig.  53, 


Fig.  53. 


and  the  perspective  view,  Fig.  54,  shows  the  form  of  tables  and 
other  mechanical  details  connected  with  the  hand  method  of 
scouring  leather. 

This  manner  is  laborious  and  expensive,  which  has  caused  it 
to  be  superseded  almost  entirely  by  machinery. 

The  Vaughn  Machine  Co.,  Peabody,  Mass.,  make  brushes 

(  208) 


SCOURING.  209 

suitable  for  scouring  by  hand.  These  brushes  are  of  excellent 
quality,  made  from  selected  bristle. 

monk's  scouring  machine. 

The  Monk  scouring  machine,  shown  in  Figs.  55  and  56,  is 
built  by  the  American  Oak  Leather  Company,  Cincinnati,  O., 
and  it  is  the  simplest,  most  durable,  and  cheapest  scouring 

Fi<;.  54. 


machine  on  the  market,  and  will  do  more  work  per  hour  with 
less  power  than  any  other  scouring  machine  which  we  have  ever 
seen.  It  should  be  run  at  a  speed  of  five  hundred  to  six  hun- 
dred revolutions  per  minute. 

It  can  be  used  on  the  following  leathers :  sole,  harness  and 
upper,  and  it  is  especially  adapted  for  scouring  shoe  leather 
splits,  as  it  prepares  the  face  of  the  split  leather  better  and  the 

14 


2IO 


THE  MANUFACTURE  OF  LEATHER. 


split  will  finish  up  finer  than  if  scoured  on  any  other  machine. 
It  is  also  especially  adapted  for  scouring  belt  leather,  as  it 
scours  the  leather  more  thoroughly  and  it  will  do  more  work 
than  any  other  machine  of  its  class  used  in  the  trade. 


Fig.  55. 


VIEW  OF  CYLINDER  SHOWING  STONES  IN  MONK'S  SCOl'KING  MACHINE. 


It  has  been  found  by  experience  that  the  fine  North  River 
blue  stone  in  the  cylinders  does  better  work  than  if  the  cylin- 
ders were  filled  with  stones  and  brushes.  But  this  is  a  matter 
for  the  purchaser  of  the  machine  to  decide,  who  can  have  the 
cylinders  filled  with  stones  or  brushes  as  he  may  desire. 

The  leather  adjusts  itself  to  the  stones  during  the  scouring. 
The  stones  are  not  made  the  full  length  of  the  cylinder.  Short 


SCOURING. 


211 


212 


THE  MANUFACTURE  OF  LEATHER. 


stones  cover  the  openings  or  gaps  left  by  the  preceding  stones, 
as  is  shown  in  the  illustration. 

The  same  machine  can  be  used  as  a  brushing  machine  for 
all  kinds  of  leather  which  may  require  brushing,  by  simply  fill- 
ing the  cylinder  with  brushes  instead  of  stones. 

Fig.  57  shows  the  new  vertical  or  upright  constructed  scour- 
ing and  setting-out  machine,  built  by  the  Vaughn  Machine 
Company,  Peabody,  Mass.  The  builders  claim  for  this  machine 
a  great  gain  in  both  quantity  and  quality  of  work  over  any- 
thing before  known  in  the  currying  shop. 

It  will  scour  or  set  out,  in  the  most  superior  manner,  large 
quantities  of  upper  leather,  in  grains,  buff,  glove,  bag  leather, 
fancy  colors,  wax,  kips,  splits  or  calf  skins,  and  belting  leather, 
either  in  the  whole  butts  or  in  strips. 

Its  construction  will  at  once  recommend  it  for  these  purposes, 
as  being  simple,  effective,  and  of  the  proper  principle  for  doing 
the  work,  as  the  side,  hide  or  skin,  is  placed  lengthways  on  the 
vertical  table,  one-half  on  each  side  of  the  same,  and  is  carried 
up  between  the  two  cylinders,  which  are  revolving  toward  each 
other,  and  covered  with  blades  arranged  so  as  to  thoroughly 
work  and  stretch  the  leather  both  in  width  and  length  at  one 
and  the  same  time,  as  will  be  seen  by  the  cut  of  the  machine. 
As  much  or  as  little  pressure  of  the  cylinders  is  applied  to  the 
leather  as  is  wanted  by  the  operator,  with  the  foot  lever.  In 
this  way  the  leather  is  much  more  thoroughly  stretched,  worked 
fine,  and  made  firmer  than  it  is  possible  to  do  by  hand  or  any 
other  machine. 

In  scouring,  as  will  readily  be  seen  from  the  cut  and  this 
description,  nothing  could  possibly  equal  its  principle,  as  the 
revolving  cylinders  thoroughly  work  out  all  the  dirt,  put  the 
leather  into  perfect  shape,  and  leave  it  fine,  dry,  even  and 
smooth;  a  great  point  being  that  all  the  dirt,  water,  tan 
liquors,  etc.,  expressed  from  the  leather  by  the  cylinders  dur- 
ing this  operation,  fall  to  the  floor,  away  from  the  table,  and 
therefore  cannot  be  absorbed  by  the  leather  again,  as  is  the 
case  in  hand  work  or  flat  table  machines. 


2  14 


THE  MANUFACTURE  OF  LEATHER. 


For  setting  out  fancy  colored  leathers  the  above  points  make 
it  particularly  valuable,  and  for  setting  out  stuffed  leather  of  all 
kinds,  a  great  point  is  that  it  can  be  worked  in  a  much  colder 
and  harder  state  than  is  possible  to  do  by  hand,  thereby  leav- 
ing the  grease  and  weight  in  the  leather,  and  having  all  the 
stretch  that  is  set  out,  stay  out. 

The  builders  guarantee,  therefore,  that  by  the  use  of  this 
machine  the  currier  gets  finer  leather,  and  at  the  same  time 
more  measurement  and  weight,  besides  the  saving  in  labor. 

Made  in  all  sizes  from  a  5  ft.  to  a  12  ft.  in  length  of  the  cylin- 
ders. 

But  little  power  and  small  space  required  to  operate  it. 
It  is  simple,  strong  and  durable. 


CHAPTER  XV. 


STUFFING  LEATHER  ;   OILS  AND  FATS  J  TESTING  OILS  ;  WATER- 
PROOF STUFFING  ;  WATER-PROOFING  LEATHER. 

HAND  STUFFING. 

IN  the  manufacture  of  upper  leather,  after  the  sides  have 
been  scoured  as  described  in  the  preceding  chapter,  they  are 
exposed  to  the  air  to  harden  and  are  next  carried  to  the  cellar 
of  the  shop  to  be  dampened  and  tempered,  so  as  to  facilitate 
the  absorption  of  the  grease;  the  tempering  process  generally 
extending  through  two  days. 

The  period  of  tempering  depends  upon  whether  the  leather 
is  to  be  stuffed  by  hand  or  machinery.  When  stuffed  by  hand 
the  leather  requires  to  be  damper  than  when  stuffed  by  means 
of  the  wheel. 

Ordinarily  the  hand  process,  of  stuffing  leather  is  accom- 
plished after  rolling  the  sides  into  bundles  with  the  grain  side 
in  and  softening  them  by  treating  or  beating,  and  then  apply- 
ing to  the  flesh  side  by  means  of  a  brush,  a  mixture  of  oil  and 
tallow  in  a  heated  state.  In  addition  to  the  trouble  and  ex- 
pense of  the  hand  method  of  stuffing,  another  objection  arises 
from  the  fact  that  the  leather  has  to  be  dampened  to  such  an 
extent  that  it  necessitates  a  long  period  for  drying,  and  then 
again,  after  the  partial  absorption  of  the  oleaginous  and  fatty 
materials,  the  surface  of  the  leather  has  to  be  separately  cleaned 
of  the  unabsorbed  matter. 

Another  great  objection  to  the  hand  method  of  stuffing 
leather  is  that  the  stuffing  materials,  unless  great  care  be  ob- 
served, penetrate  only  slightly  beyond  the  surface,  thereby 
leaving  the  leather,  as  regards  the  main  body,  dry  and  un- 
changed, and  consequently  hard.    But  when  the  modern  stuff - 

(  215  ) 


2l6  THE  MANUFACTURE  OF  LEATHER. 

ing  drum  is  used  for  this  purpose  the  leather  is  usually  thor- 
oughly permeated  and  thereby  rendered  soft  and  pliable. 

The  old  method  of  hand  stuffing  is  now  passing  away  and  in 
modern  currying  shops  it  is  only  used  for  certain  classes  of 
leathers. 

DRUM  STUFFING. 

Drum  stuffing  is  the  most  profitable,  and  turns  out  a  more 
salable  article.  In  these  days  of  close  competition,  i  pound 
in  weight  in  a  dozen  kip  butts,  or  a  pair  of  harness  backs  or 
strap  butts,  is  a  very  important  item,  especially  if  the  same  can 
be  obtained  leaving  the  goods  a  better  color  and  a  more  sal- 
able appearance  than  if  done  by  hand.  It  must  always  be  re- 
membered that  stale  goods  will  not  carry  the  stuff  as  well  as 
fresh  ones,  and  goods  that  have  had  a  good  sumaching  will, 
as  a  rule,  carry  the  stuff  more  freely.  In  preparing  the  goods 
they  should  be  dried  out  and  then  dampened  on  the  flesh  and 
grain  sides  and  allowed  to  lie  in  a  pile  for  a  time  covered  with 
damp  cloths,  so  that  the  moisture  permeates  freely  through  the 
leather,  but  not  sufficiently  so  that  the  water  can  be  squeezed 
out. 

The  next  point  is — what  is  the  best  material  to  use  in  stuff- 
ing? This  depends  on  the  quality  of  the  goods  ;  if  they  are 
of  the  best  quality,  we  recommend  the  best  grade  of  tallow 
and  cod  oil,  no  matter  whether  harness,  strap  or  shoe  work ; 
but  if  they  are  of  second  or  inferior  quality,  and  especially  if  the 
goods  are  being  dressed  for  the  market,  we  would  say  that 
there  is  nothing  to  beat  stearine,  mixed  with  degras  and  neat's- 
foot  oil. 

It  is  not  possible  to  lay  down  any  fixed  rule  for  stuffings,  as 
all  depends  upon  the  quality  of  the  tannage,  and  the  grade  of 
leather  which  it  is  desired  to  produce.  The  temperature  of  the 
drum  and  the  temperature  of  the  stuffing  are  also  points  which 
must  be  influenced  by  the  same  considerations. 

In  heating  the  drum  close  the  door  and  turn  on  the  steam 
for  20  minutes,  the  drum  remaining  stationary,  ihen  turn  off  the 


STUFFING  LEATHER. 


217 


steam  and  disconnect  the  pipe.  It  is  very  important  that  the 
steam  pipe  should  be  disconnected  each  time,  because  after  a 
little  wear  there  is  sure  to  be  an  escape  of  steam,  more  or  less, 
and  consequently  the  scalding  of  goods,  which  is  a  very  serious 
matter.  After  disconnecting  the  pipe,  take  off  the  door  and 
allow  the  drum  to  run  for  five  minutes,  so  that  the  steam  may 
evaporate,  then  put  in  the  goods  as  quickly  as  possible,  and 
put  on  the  skeleton  door,  and  let  them  run  for  a  few  minutes 
before  putting  in  the  stuff" ;  by  so  doing  the  goods  will  become 
broken  up  and  more  regulated  ;  then  stop  the  drum,  put  in  the 
stuff,  and  put  on  the  close  door  and  run  the  goods  for  forty 
minutes.  The  stuff  must  be  put  in  warm,  of  course,  but  not  hot 
enough  to  scald  the  goods.  After  running  for  forty  minutes, 
take  off  the  close  door  and  again  put  on  the  open  door,  and 
run  the  goods  for  another  five  minutes  ;  that  will  allow  the  goods 
to  cool  down  and  become  more  even.  The  putting  on  of  the 
open  door  is  simply  to  prevent  the  goods  from  falling  out  as 
the  drum  is  revolving. 

The  goods  may  now  be  taken  out  and  opened  out  smoothly 
in  a  pile,  and  if  they  are  not  wanted  for  setting  immediately 
they  should  be  covered  and  kept  as  warm  as  possible,  until 
such  time  as  they  are  wanted  for  setting.  What  is  best  after 
taking  from  the  drum  is  to  place  the  goods  in  an  air-tight  box, 
until  such  time  as  they  are  needed.  By  keeping  the  goods 
moist  and  keeping  them  warm  much  labor  will  be  saved  in 
setting,  and  they  will  look  much  better  for  it.  It  is  best  to 
set  the  goods  as  early  as  possible  after  removal  from  the  drum, 
for  if  they  are  allowed  to  become  cool,  it  is  almost  impossible  to 
get  out  the  stretch.  When  the  goods  are  unavoidably  allowed  to 
lie  and  get  cold,  it  is  well  to  have  a  tub  of  water  by  the  side  of 
the  stuffing  table,  and  dip  in  each  side  to  soften  it  before  pro- 
ceeding to  set  the  same.  In  setting,  we  recommend  the  use  of 
marble  or  plate-glass  tables,  as  they  do  not  leave  any  impres- 
sion on  the  flesh  side  after  stoning,  but  give  a  smooth  and  close 
appearance  to  the  flesh  side,  thereby  saving  both  leather  and 
labor  in  whitening.    The  goods  should  be  stoned  on  the  grain 


218 


THE  MANUFACTURE  OF  LEATHER. 


with  fine  stone,  until  all  old  or  growth  grain  is  removed,  then 
hung  up  nearly  dry;  then  again  take  down  and  glass  on  the 
grain,  removing  all  stone  marks,  and  giving  pattern  to  the 
leather;  then  again  hung  up  until  dry. 

REED  AND  WINCHES  1  ER'S  STUFFING  DRUM. 

The  stuffing  drum  shown  in  Figs.  58  and  59  is  the  invention 
of  Reed  and  Winchester. 

This  invention  in  stuffing  leather  has  for  its  object  a  method 
whereby  the  grease  may  be  put  into  the  leather  more  regularly 
than  heretofore.  The  leather  must  be  warm,  and  be  kept  warm 
uniformly  during  the  time  the  grease  is  being  applied  to  it. 

The  leather  to  receive  grease  or  stuffing  is  usually  placed  in 
a  rotating  drum  or  wheel  previously  heated  by  steam  or  hot  air 
blown  into  it  while  the  wheel  is  empty,  for  it  has  been  found 
that  steam  injected  into  the  drum  in  the  presence  of  the  leather 
is  apt  to  burn  it.  A  drum  heated  only  before  placing  the  leather 
in  it  commences  to  cool  immediately  thereafter,  and  the  stuffing 
or  greasing  operation  is  retarded.  Another  serious  objection  to 
the  direct  introduction  of  steam  into  the  drum  with  the  leather 
and  grease  is  that  arising  from  water  of  condensation,  as  even 
a  small  amount  of  water  added  at  that  time,  the  leather  having 
been  evenly  and  sufficiently  moistened  before  it  was  placed  in 
the  drum,  will  be  taken  up  by  the  leather,  thus  lessening  the 
amount  of  grease  entering  the  leather  at  that  spot  where  the 
water  of  condensation  in  the  grease  meets  the  leather,  and, 
further,  the  heat  derived  from  free  steam  varies  materially, 
according  to  the  pressure  of  steam  in  the  boiler.  To  obviate 
the  objection  of  free  steam  the  drum  has  been  placed  in  a  sec- 
ond drum  heated  by  steam. 

In  this  invention  the  interior  of  the  drum  and  leather  therein 
are  kept  at  the  desired  temperature  by  means  of  heated  air 
forced  therein  while  the  drum  containing  its  charge  of  leather 
is  being  rotated.  The  hot  air  is  supplied  to  the  drum  by  a 
blower  or  pump  through  pipes,  in  connection  with  a  receiving- 
chamber  of  a  suitable  heat-generating  apparatus. 


STUFFING  LEATHER. 


Figure  58  represents,  in  vertical  section,  an  apparatus  em- 
bodying Reed  and  Winchester's  invention,  the  wall  of  the  heat- 
generating  apparatus  being  also  in  section.  Fig.  59  is  an 
elevation  of  the  left-hand  end  of  the  drum,  the  latter  being 
partially  broken  out. 

The  drum,  a,  about  seven  feet  in  diameter,  has  a  door,  b,  for 
the  introduction  of  the  leather  therein,  and  a  series  of  pegs,  c, 
at  suitable  intervals  apart  to  lift  and  tumble  the  leather  as  the 
drum  is  rotated,  all  as  usual.  This  drum  has  at  one  journal  a 
pipe,  d,  for  the  introduction  at  suitable  times  of  hot  grease,  and 
at  its  other  journal  it  has  a  pipe.r,  for  the  continuous  admission 
of  hot  air  while  the  drum  is  being  rotated  with  the  leather  and 
grease  therein.  The  pipe  c  is  preferably  placed,  in  coil  or  other 
form,  in  the  combustion-chamber  /,  heated  in  any  usual  way, 
so  that  air  forced  through  the  pipe  by  an  air-forcing  apparatus, 


Fic.  58. 


g  (shown  as  a  blower,  but  which  might  be  a  pump),  will  be 
heated  before  reaching  the  drum.  The  side  of  the  drum  will 
be  provided  with  openings  of  suitable  size  for  the  escape  of  the 
heated  air,  so  as  to  maintain  proper  circulation.  The  air  so 
escaping  might  be  delivered  into  an  annular  chamber,  //,  placed 
next  to  the  openings  of  the  wheel  (see  Fig.  58 ),  having  a  pipe, 
i,  to  lead  the  air  out  of  the  building,  if  desired. 


220 


THE  MANUFACTURE  OF  LEATHER. 


The  air-pipe,  at  a  point  between  the  chamber  f  and  drum, 
may  have  a  branch,  k,  by  which,  if  desired,  to  divert  the  heated 
air  into  a  water-box  and  over  a  pan  of  water,  to  thus  add  a 
little  moisture  to  the  hot  air,  if  too  dry;  or  we  may  inject  a 
small  amount  of  steam  into  the  pipe  e  containing  the  hot  air,  to 
slightly  moisten  it,  care  being  taken  to  so  regulate  the  steam 
that  no  water  of  condensation  is  permitted  to  form  or  enter  the 
drum. 

In  this  process  it  is  possible  to  keep  the  interior  of  the  drum 
and  the  leather  therein  at  a  uniform  temperature,  which  may  be 

Fig.  59. 


i 


indicated  by  a  thermometer  properly  connected  with  the  drum, 
which  enables  the  leather  to  be  greased  or  stuffed  uniformly 
and  rapidly,  and  that  without  fear  of  injuring  the  leather  in  any 
way  by  over-heating,  as  when  steam  is  depended  upon,  or  by 
too  rapid  cooling,  as  when  the  drum  is  heated  only  before  ap- 
plying the  leather.  The  grease,  in  proper  quantities,  can  be 
introduced  from  time  to  time,  as  needed. 

This  valuable  invention  appears  to  have  been  suggested  by 
that  of  Dr.  Friederich  Knapp,  of  Brunswick,  Germany,  who  in- 
vented an  improvement  in  tramping-drums  in  1878,  which  pos- 
sessed the  combination  of  the  drum  and  hollow  trunnions  and 


STUFFING  LEATHER. 


22  I 


the  blower  or  fan  and  other  arrangements  very  similar  to  the 
stuffing  wheel  which  has  just  been  described  ;  but  while  our 
Government  granted  Knapp  a  patent  for  the  fan  attachment 
to  the  stuffing  wheel,  the  German  Government  had  previously 
refused  it  as  not  being  a  new  idea. 

freeman's  stuffing  drum. 
J.  T.  Freeman  &  Co.,  Woburn,  Mass.,  manufacture  all  kinds 
of  stuffing  and  tanning  drums,  driven  either  with  a  gear  on  the 
outside  or  on  the  end,  as  shown  in  Fig.  60,  as  parties  may 
desire. 


Fi<;.  60. 


The  machines  made  by  this  firm  are  all  put  together  in  the 
best  possible  manner,  and  are  in  every  way  fitted  for  the  work 
required  of  them,  and  they  offer  them  to  the  trade,  feeling  that 
they  will  prove  completely  satisfactory,  and  they  guarantee 
them  to  be  in  all  respects  as  represented.  Their  machines  are 
in  use  in  the  establishments  of  nearly  all  leading  tanners  and 
curriers  in  the  United  States. 

curriers'  oils  and  grease. 
Oil  is  the  general  name  for  a  class  of  bodies  which  have  all 


222 


THE  MANUFACTURE  OF  LEATHER. 


or  most  of  the  following  properties  in  common :  They  are 
neutral  bodies,  having  a  more  or  less  unctious  feel  and  viscous 
consistency,  are  liquid  at  ordinary  temperatures,  are  lighter 
than  water,  and  are  insoluble  in  it,  but  dissolve  in  alcohol  and 
more  readily  in  ether,  and  take  fire  when  heated  in  air,  burning 
with  a  luminous,  smoky  flame. 

The  name  oil  is  made  to  embrace  three  distinct  classes  of 
bodies:  I,  fixed  or  fatty  oils;  2,  volatile  and  essential  oils,  and 
3,  petroleum  and  other  mineral  oils.  The  first  class  comprises 
a  number  of  organic  bodies,  composed  of  carbon,  hydrogen 
and  a  little  oxygen,  viscid  liquids,  communicating  a  permanent 
stain  to  paper,  insoluble  in  water,  and  as  they  occur  in  nature, 
mostly  mixtures  of  different  simple  fats,  which,  by  saponifica- 
tion, are  resolved  into  fatty  acids  and  glycerine.  The  term  fat 
is  applied  to  these  oils  when  they  are  in  a  solid  state ;  thus  the 
same  product  may  be  an  oil  in  one  climate  and  a  fat  in  another. 
The  second  class,  volatile  and  essential  oils,  consist  either 
wholly  of  carbon  and  hydrogen,  or  of  these  elements  supple- 
mented by  less  proportions  of  oxygen,  nitrogen  and  sulphur. 
They  have  a  thin,  oily  consistence,  volatilize  completely  at  a 
high  temperature,  possess  powerful  and  peculiar  odor  and  flavor, 
and  are  very  inflammable  and  sparingly  soluble  in  water.  Many 
of  them  occur  ready  formed  in  organic  bodies,  chiefly  of  the 
vegetable  kingdom,  and  are  then  true  essential  oils ;  others, 
which  are  volatile  but  not  essential,  are  produced  by  dry  dis- 
tillation, fermentation  and  other  changes.  The  third  class, 
mineral  oils,  belong  strictly  to  the  preceding,  being  truly  vola- 
tile oils. 

In  a  fresh  state  the  fats  are  odorless,  tasteless,  colorless  or 
white  bodies,  which  may  be  either  solid  or  liquid.  They  are 
insoluble  in  water  and  cold  alcohol,  but  dissolve  freely  in  ether, 
chloroform  and  benzine.  The  solid  neutral  fats,  like  sperma- 
ceti, suet  and  lard,  and  the  liquid  non-volatile  oils,  like  sperm 
and  olive  oil,  are  classed  together  as  fats.  They  are  compound 
ethers  formed  by  the  union  of  fatty  acids  with  the  triatomic 
alcohol  glycerine.  They  are  composed  of  carbon,  hydrogen 
and  oxygen,  but  contain  no  nitrogen. 


STUFFING  LEATHER. 


223 


The  most  common  and  abundant  are  stearin,  palmitin  and 
olein.  Of  these,  stearin  and  palmitin  are  solids  at  ordinary 
temperatures,  and  olein  is  a  liquid.  Most  animal  and  vegetable 
fats  are  mixtures  of  two  or  more  of  the  simple  fats,  and  their 
hardness  depends  largely  on  the  relative  quantity  of  olein  or 
other  liquid  fat  in  them.  When  a  fat  is  treated  with  an  alkali, 
the  fatty  acid  unites  with  the  alkaline  base,  making  a  soa,p,  and 
glycerine  is  set  free.  When  a  soap  is  treated  with  an  acid,  the 
base  is  taken  from  the  fatty  acid,  which  is  thus  set  free. 

Neither  essential  nor  mineral  oils  can  be  spoken  of  as  fatty 
substances.  So  far  as  these  are  of  interest  to  tanners  and  cur- 
riers they  will  be  here  described. 

For  leather  there  is  probably  no  oil  that  combines  so  many 
points  of  excellence  as  strictly  pure  cod  oil,  which  is  obtained 
from  cod  liver,  and  is  produced  in  quite  large  quantities,  and 
has  stood  the  test  of  experience  and  trial  for  a  very  long  period 
of  years,  dating  back  to  the  earlier  stages  of  the  leather  industry. 

The  reasons  for  the  excellence  of  cod  oil  for  leather  purposes 
are  not  hard  to  find. 

In  the  first  place,  it  has  a  splendid  body,  and  imparts  to  the 
leather  a  permanent  mellow  feeling,  by  reason  of  its  freedom 
from  oxidizing  (caused  by  absorption  of  oxygen  from  the  air) 
common  to  a  great  many  other  oils. 

Cod  oil  absorbs  oxygen,  or  in  other  parlance,  gums,  to  the 
smallest  appreciable  extent  only,  and  for  that  reason,  together 
with  its  great  body  and  freedom  from  evaporation,  remains  in 
the  leather  under  the  same  conditions  practically,  in  which  it 
was  originally  put  in. 

The  best  quality  of  cod  oil  comes  from  the  Newfoundland 
Fisheries,  where  the  method  of  extracting  the  oil  from  the  liver 
in  a  cool  atmosphere,  extracts  only  the  cream  of  the  oil,  which 
is  very  rich  and  contains  the  minimum  of  animal  fibre,  blood, 
gluten,  etc.,  thereby  insuring  the  very  best  results. 

This  oil  commands  the  highest  price  in  the  market,  and  is 
worth  the  difference  in  cost  between  it  and  cheaper  grades,  or 
any  adulterations. 


224 


THE  MANUFACTURE  OF  LEATHER. 


Some  of  the  adulterants  used  by  unscrupulous  dealers  are 
mineral  oils  of  various  kinds,  including  paraffine  oil,  as  well  as 
brown  seal  and  menhaden  oils. 

Cod-liver  oil  is  a  valuable  oil  afforded  by  the  liver  of  several 
fish  of  the  genus  T}adus,  notably  that  of  the  common  cod.  The 
chief  seats  of  the  cod-fishery  are  the  coasts  and  banks  of  New 
Foundland,  Nova  Scotia,  the  Gulf  of  St.  Lawrence,  the  west 
coast  of  Norway,  from  Stavenger  nearly  up  to  Hammerfest,  and 
including  the  Loffoden  Islands;  the  coasts  of  Denmark  and 
Germany,  commencing  at  Romo  on  the  west,  passing  through 
the  Skager  Rack  and  Cattegat,  and  extending  east  to  Dant- 
zig ;  the  coasts  of  Shetland,  Faroe  and  Iceland,  the  Dogger 
Bank  in  the  North  Sea,  and  the  most  prolific  of  all,  the  shores 
of  Alaska  in  the  Pacific  Ocean.  The  most  usual  classification 
for  cod-liver  oil  is  into  1st,  steam-boiled  medicinal  or  ordinary 
bright;  2d,  an  inferior  "light  brown,"  and  3d,  the  "dark 
brown"  or  "tanners',"  obtained  by  roughly  boiling  down  the 
livers  remaining  after  the  other  two  oils  have  been  extracted. 
The  best  is  said  to  be  from  New  Foundland.  The  chemical 
and  physical  characteristics  of  the  3d  grade,  the  only  one  in 
which  we  are  interested,  are  as  follows :  The  color  is  dark 
brown,  greenish  by  transmitted  light;  specific  gravity  0.929, 
at  63  y2°  F. ;  soluble  in  1  7-20  parts  cold  or  hot  absolute  alcohol ; 
deposits  no  solid  fat  at  900  F.  The  oil  consists  chiefly  of 
oleine  and  margarine,  and  contains  small  portions  of  iodine, 
bromine,  and  free  phosphorus,  besides  peculiar  constituents. 
Many  other  oils  are  substituted  for  true  cod-liver  oil.  That 
obtained  from  the  ling,  the  liver  of  the  dorse,  and  of  the  coal- 
fish,  the  barbot,  the  haddock,  hake,  cat-fish,  conger  eel,  ray, 
shark,  and  probably  many  others,  are  surreptitiously  mingled 
with  the  cod-liver  oil  of  commerce. 

Genuine  cod  oil  is  made  wholly  from  the  liver  of  the  fish, 
while  menhaden  oil  is  squeezed  from  the  body  of  the  fish. 
The  latter  oil  has  more  gum  or  glutinous  matter  than  the  gen- 
uine cod  oil.  Mineral  oil  improves  it  by  cutting  the  gum,  and 
this  is  the  reason  that  cheap  cod  oils  are  often  used  without 


STUFFING  LEATHER. 


225 


trouble.  Cod  oil  and  menhaden  oil  are  of  the  same  color  and 
gravity,  and  resemble  each  other  as  to  odor  and  taste.  These 
similar  properties  make  deception  very  easy.  A  better  and 
more  economical  way  than  to  buy  cheap  "cod  oil"  is  to  buy 
pure  pressed  menhaden  oil  and  buy  paraffine  oil  and  combine 
the  two  oils  in  the  proportions  wanted.  The  pure  cod  oil  is, 
however,  everything  considered,  cheapest  in  the  end.  As  long 
as  dealers  are  determined  to  get  large  profits  and  tanners  are 
deceived,  the  selling  of  cheap  fish  oils  for  cod  oil  will  continue. 

Mineral  oils  are  easily  detected  by  several  well-known  tests, 
such  as  the  gravity  test,  as  the  admixture  of  mineral  oils  re- 
duces its  body  or  substance,  and  when  compared  with  strictly 
pure  oil,  the  difference  can  at  once  be  seen.  Another  method 
of  detecting  mineral  oil  is  by  saponifying  the  fatty  oil,  whereby 
the  mineral  oil,  which  will  not  saponify,  will  separate.  Another 
method  is  to  distil  off"  the  mineral  oil  by  heat  of  about  4400 
Fahrenheit,  thus  leaving  the  non-volatile  oil  behind. 

Adulterations  of  brown  seal  and  menhaden  oils  are  almost  im- 
possible to  detect  chemically,  but  the  bad  effects  will  appear 
only  after  the  leather  has  been  finished,  when  it  is  too  late  to 
remedy  them. 

The  only  safeguard  for  the  tanner  is  to  obtain  goods  from 
strictly  reliable  houses  only,  of  known  reputation,  and  to  take 
only  such  brands  as  are  known  to  be  strictly  and  absolutely 
pure  and  as  represented. 

Considerable  quantities  of  cod  oil  are  produced  in  the  Pro- 
vinces, and  also  from  the  various  Fisheries  in  the  United  States, 
the  general  principle  being  that  the  deep-sea  oil,  made  in  a 
cool  temperature,  and  thoroughly  rendered,  produces  the  best 
results. 

Bank  and  Straits  oils  are  used  as  substitutes  for  cod  oil  and 
for  some  purposes  seem  to  answer  very  well.  Both  of  these 
kinds  are  subject  to  absorption  of  oxygen,  or  in  other  words, 
gumming,  when  exposed  to  the  air,  Straits  oil  being  a  little 
lighter  in  color,  and  generally  bringing  one  or  two  cents  more 
per  gallon. 

*5 


226 


THE  MANUFACTURE  OF  LEATHER. 


Degras,  the  imitation  variety,  is  a  wool  grease,  reclaimed  from 
washing  of  wool,  and  varies  in  excellence  owing  to  the  kind  of 
wool  washed,  the  method  of  saponification  or  scouring  soap 
used  in  the  process,  and  thirdly,  upon  the  method  of  recover- 
ing the  grease. 

Where  either  of  these  methods  is  poor,  the  resultant  grease 
is  bad.  There  is  therefore  quite  a  range  in  price  to  correspond 
with  the  different  qualities. 

Some  degras  is  not  fit  for  use  on  leather,  as  it  is  imperfectly 
made  or  not  properly  purified. 

Large  quantities  are  imported  into  the  United  States  from 
England,  France  and  Germany,  but  great  care  should  be  exer- 
cised to  secure  the  proper  goods  in  order  to  obtain  the  best 
results.    The  true  degras  comes  from  France. 

It  is  safer  to  use  only  the  best  and  well-known  brands,  which 
are  carefully  and  uniformly  made,  and  are  by  test  and  experi- 
ence known  to  be  of  uniform  quality  and  excellence.  Among 
such  reliable  goods,  which  have  been  on  the  market  and  most 
favorably  known  for  a  great  many  years,  are  the  "Anchor" 
and  the  "  Merino." 

English  sod  oil' is  a  product  resulting  in  the  oil  tannage  of 
skins,  which  are  allowed  to  heat  slightly  by  exposure  to  the  at- 
mosphere in  moderately  warm  temperature,  and  the  excess  of 
oil  is  thereafter  pressed  out,  or  washed  out  with  a  weak  alkali, 
as  the  case  may  be,  some  employing  both  methods  and  some 
only  one  in  extraction ;  but  as  a  rule,  both  are  used,  and  the 
resultant  oil  makes  the  sod  oil  of  commerce. 

It  will  be  at  once  apparent  that  there  is  an  opportunity  for  a 
great  variation  in  quality  of  sod  oil,  dependent  upon  the 
methods  employed,  the  kind  of  skins  treated,  and  the  kind  of 
oil  originally  used  for  tanning.  Therefore,  the  currier  must  be 
careful  to  buy  only  those  kinds  that  he  knows  are  adapted  to 
his  particular  finish  if  he  would  get  the  best  results. 

Some  of  the  sod  oil  is  boiled  after  having  been  expressed 
from  the  skins,  and  the  water  evaporated  out.  Other  brands 
have  more  or  less  water  in  combination. 


STUFFING  LEATHER. 


227 


It  will  therefore  be  seen  at  once  that  here  is  a  chance  for 
wide  variation  in  price,  to  correspond  with  the  difference  in 
quality.  Therefore  the  experienced  purchaser  or  handler  can 
by  selection  suit  the  individual  currier  with  such  goods  as  he 
may  require. 

French  moellon  oil,  strictly  speaking,  is  an  expressed  oil 
from  chamois  tannage,  French  degras  being  a  mixture  of 
moellon  and  oil  obtained  from  washing  the  skins  in  an  alkaline 
solution. 

"Imperial"  French  moellon  is  as  good  an  article  as  there  is 
on  the  market,  and  is  always  reliable  and  sale. 

Tallow  is  not  so  generally  used  as  formerly  in  the  manufac- 
ture of  upper  leather,  because  other  harder  and  dryer  greases 
are  obtainable,  of  strictly  uniform  quality,  that  seem  to  serve 
the  purpose  better.  If  tallow  is  used  at  all,  only  the  harder  and 
purer  kinds,  that  contain  no  bone  grease  or  other  adulterations, 
should  be  used  in  order  to  get  the  best  results. 

Strictly  pure  rendered  tallow,  made  from  fresh  fat,  is  by  far 
preferable,  as  it  is  harder  and  contains  less  moisture  than  the 
ordinary  cheap  tallow  rendered  by  steam. 

Oleo-stearine,  a  product  of  the  best  suet  tallow  from  which 
the  oil  has  been  expressed,  is  considerably  used  for  stuffing  of 
leather,  and  is  a  desirable  article,  although  if  used  alone  it  does 
not  give  a  satisfactory  finish,  being  too  dry  and  husky. 

Paraffine  wax  should  not  be  used  in  large  quantities,  because 
it  has  very  little  real  body,  its  hardness  being  apparent  rather 
than  substantial.  When  melted,  it  is  a  very  thin  liquid,  of  ex- 
tremely high  gravity,  and  its  apparent  substance  is  due  to  the 
fact  that  it  chills  at  about  1250  F. 

The  principal  stuffing  used  for  upper  leather  is  a  brown,  hard 
grease,  made  principally  from  rendered  whitening  and  table 
grease,  and  this  compound  seems  to  give  better  results  and 
produce  leather  of  more  uniform  excellence  than  any  other 
grease  now  before  the  public. 

The  reason  for  this  is  not  hard  to  find,  for  the  material  is 
virtually  a  stearine,  from  which  the  oil  has  been  absorbed  in- 


228 


THE  MANUFACTURE  OF  LEATHER. 


stead  of  pressed,  thus  making  a  desirable  compound  of  the 
right  body  to  thoroughly  fill  the  leather,  and  at  the  same  time 
make  it  mellow  and  good. 

Competition  has  brought  the  price  down  to  the  lowest  figure 
ever  known,  and  the  best  brands  are  obtainable  at  prices  nearly 
as  low  as  ordinary  tallow. 

The  "  Ideal"  grease  probably  combines  as  many  points  of 
excellence  as  anything  in  the  market,  and  its  use  is  rapidly  ex- 
tending, especially  for  split,  grain  and  satin  leather.  In  the 
manufacture  of  this  grease  comparatively  new  methods  are 
employed,  and  the  result  is  a  scientific  compound  which  pro- 
duces the  best  stock  at  a  minimum  price.  This  grease  is  pre- 
pared by  Frank  L.  Young  and  Kimball,  Boston,  Mass. 

Neatsfoot  oil  is  used  largely  in  the  manufacture  of  kid  and 
skins  of  various  kinds,  and  works  very  well  if  care  is  taken  to 
secure  oil  that  has  been  refined  sufficiently  to  stand  a  first-rate 
cold  test.  Otherwise  the  skin  is  liable  to  turn  white  after 
being  finished  and  exposed  to  a  cold  temperature. 

A  great  deal  of  damage  may  be  done  by  using  impure  or 
imperfectly  manufactured  oil,  and  great  care  should  be  exer- 
cised in  getting  the  right  kind  of  goods. 

The  Vici  brand  of  neatsfoot  oil  is  a  well-known  brand  which 
has  stood  the  test  of  years  and  experience. 

MENHADEN,  STRAITS  OR  BANK  OIL 

A  fish  once  eagerly  sought  for  its  oil  on  the  Atlantic  coast  is 
the  menhaden,  pogy,  mossbunker,  bony  fish,  chebog,  as  it  is  var- 
iously called,  (alosa  brevoordia  menhaden),  a  member  of  the 
herring  family,  about  eight  to  fourteen  inches  long.  The  fish- 
ery is  carried  on  all  along  the  coast  from  Maine  to  Maryland. 
The  fish  leave  the  Gulf  Stream  and  strike  the  coast  of  New 
Jersey  in  April,  reaching  the  coast  of  Maine  in  May  or  June, 
and  remaining  till  October  or  November.  They  migrate  in 
enormous  schools  and  are  caught  in  seines.  These  fish  are 
nearly  all  boiled  down  to  oil  in  steam  kettles  and  exposed  to 
hydraulic  pressure  ;  the  scrap  being  utilized  for  fertilizers.  The 


STUFFING  LEATHER. 


229 


oil  is  clarified  and  bleached  by  boiling  and  filtering.  Thus 
refined  it  is  called  "  straits."  Bank  oil  is  an  inferior  grade. 
Bleaching  the  oil  is  done  by  exposing  it  to  the  sun  in  glass- 
covered  shallow  tanks.  Owing  to  the  tendency  of  menhaden 
oil  to  gum,  it  is  not  much  used  now  in  the  leather  industry. 

PORPOISE  OIL. 

Porpoise  oil  embraces  the  oils  obtained  from  the  black  por- 
poise, the  white  whale,  the  grampus  and  the  blackfish.  A  full 
grown  porpoise  attains  a  weight  of  2,500  to  4,000  pounds,  and 
gives  some  400  to  450  pounds  of  oil,  which  is  more  esteemed 
than  that  of  either  the  seal  or  walrus.  These  animals  are  taken 
by  being  surrounded  by  enclosures  made  of  light  flexible  poles 
driven  into  the  beach,  within  which  they  are  speared  and 
harpooned  from  boats.  The  oil  is  inodorous  and  gives  a  bril- 
liant light,  it  congeals  only  in  intense  cold,  and  its  softness 
renders  it  valuable  for  lubricating  and  leather  dressing. 

The  oil  obtained  from  the  head  of  the  grampus  is  thought  to 
be  even  superior  to  any  yet  obtained  from  the  porpoise  and  the 
black-fish,  but  this  cetacean  occurs  much  more  rarely  than 
either  of  the  animals  just  described. 

TUNNY  OIL. 

The  tunny  is  second  in  importance  only  to  the  sardine 
among  the  fish  caught  in  the  Mediterranean.  This  fish  yields 
a  very  large  quantity  of  oil  which  is  extracted  by  boiling,  which 
operation  is  performed  in  the  crudest  possible  manner.  Tunny 
oil  is  of  a  pale  amber  color,  and  possesses  more  body  than 
any  other  fish  oil.  It  is  very  commonly  adulterated  with  in- 
ferior cod  oil  and  cotton-seed  oil.  That  prepared  at  Genoa  is 
said  to  be  superior  to  all  others. 

NEATS'  FOOT  OIL. 

Neats'  foot  oil  is  made  from  "  ox  feet,"  the  feet  and  hocks  of 
neat  cattle  cut  off  about  eighteen  inches  above  the  hoof,  and 
is  a  valuable  oil.    It  is  prepared  by  denuding  the  feet  of  skin 


230 


THE  MANUFACTURE  OF  LEATHER. 


and  slitting  up  longitudinally,  by  a  knife  passed  between  the 
sections  of  the  hoof  and  continued  between  the  long  bones. 
Near  the  hoof  is  a  small  mass  of  soft  fat,  which  is  scooped  out 
with  a  knife,  and  set  aside  for  the  preparation  of  the  best 
quality  of  oil.  The  hoofs  are  washed  in  cold  water  and  then 
boiled.  A  certain  quantity  of  oil  is  thus  boiled  out  of  them, 
and  when  skimmed  off,  forms  an  inferior  grade  of  neats'  foot 
oil.  After  about  three  hours'  boiling,  the  tissues  between  the 
horny  hoofs  and  the  last  digit  bone  are  sufficiently  softened  to 
allow  of  the  latter  being  easily  scooped  out  of  the  hoof  with  a 
knife.  These  "  cores,"  consisting  of  bone,  gelatinous  matter 
and  fat,  together  with  the  small  pieces  previously  alluded  to  as 
being  removed  by  the  knife  before  boiling,  are  put  into  a 
separate  pan  of  fresh  water,  and  all  boiled  together  for  the  ex- 
traction of  the  oil.  This  forms  the  best  kind  of  neats'  foot  oil. 
The  oil  is  usually  yellowish  or  greenish  in  color,  but  that  from 
Buenos  Ayres  is  often  colorless.  It  is  odorless  when  fresh  and 
of  agreeable  flavor.  It  is  limpid  and  remains  so  below  a 
temperature  of  320  F.  Its  density  at  590  F.  is  0.916.  On 
standing  for  a  short  time,  a  proportion  of  solid  fat  separates 
out,  and  may  be  filtered  off.    It  is  very  rarely  found  pure. 

DEGRAS. 

We  have  only  to  speak  now  of  degras,  the  surplus  oil  from 
the  chamois  leather  manufacture,  which,  in  France  is  prepared 
by  daily  stocking  the  skins  with  oil,  and  hanging  in  the  air 
for  oxidation.  The  degras  is  obtained  not  by  washing  the 
skins  in  an  alkaline  lye,  as  in  the  English  and  German  method, 
but  by  simply  pressing  or  wringing.  This  oil,  altered  by  oxi- 
dation, is  so  valuable  for  currying  purposes  that  skins  are 
frequently  worked  simply  for  its  production,  being  oiled  and 
squeezed  again  and  again  till  not  a  rag  is  left.  It  is  generally 
mixed  in  commerce  with  more  or  less  of  ordinary  fish  oil. 
Eitner  recommends,  where  the  degras  is  of  indifferent  quality, 
a  mixture  of  65  parts  degras,  20  of  neutral  soap  (i.  e.  soap 
without  the  usual  excess  of  alkali),  and  15  of  soft  tallow. 


STUFFING  LEATHER. 


231 


A  degras  is  used  in  England  called  Vickers'  degras.  It  is 
more  softening  than  sod  oil,  and  carries  the  tallow  well  into  the 
leather.  Hides  left  in  it  for  some  time  are  not  darkened.  If 
stearine  is  used,  20  to  35  per  cent,  of  degras  obviates  harsh- 
ness, and  goods  will  be  firm  yet  mellow.  In  cheap  lining 
bellies,  this  degras,  used  instead  of  cod  oil,  gives  better  weight, 
lighter  color,  and  a  good  "calf"  handle.  It  is  much  cheaper 
than  French  degras. 

The  use  of  sod  oil  or  French  degras,  for  stuffing  bark-tanned 
leather,  dates  as  far  back  as  the  last  century.  At  that  time 
curriers  used  it  mainly  in  the  form  of  "  fat  liquor,"  although  a 
considerable  quantity  was  also  used  as  "  sod  oil."  At  that 
time  sod  oil  was  made  from  fat  liquor  by  decomposing  the 
same  with  alum;  otherwise  the  process  was  the  same  as  to-day, 
where  sulphuric  acid  is  used  to  "  throw  out"  the  sod  oil.  The 
use  of  sulphuric  acid  offers  no  advantage  over  alum  except 
being  a  little  cheaper,  while  on  the  other  hand,  sulphuric  acid 
is  a  very  dangerous  enemy  to  leather.  If  the  acid  used  for 
making  sod  oil  is  added  even  in  small  excess,  it  will  be  carried 
with  the  sod  oil  into  the  leather  and  there  surely  work  havoc. 
Leather  stuffed  with  such  sod  oil  is  very  liable  to  get  tender, 
and  logwood  black  will  be  apt  to  fade  if  sulphuric  acid  comes 
in  contact  with  it.  We  have  tested  numerous  sod  oils  which 
contained  quite  a  considerable  quantity  of  sulphuric  acid.  It 
is  often  thought  that  heating  a  sod  oil  will  drive  off  any  sul- 
phuric acid.  This  notion  is  erroneous,  as  sulphuric  acid  is  not 
volatile  below  5900  F.,  and  sod  oil  at  this  temperature  would 
be  burned  to  charcoal.  The  only  practical  way  of  getting  rid 
of  an  excess  of  acid  in  sod  oil  is  to  boil  it  with  a  weak  solution 
of  soda  or  other  alkali.  The  alkali  will  combine  with  the  acid 
and  leave  the  latter  powerless  to  do  any  damage.  When 
French  calfskins  had  become  renowned  for  their  superiority,  it 
was  found  out  that  the  principal  factor  of  their  stuffing  con- 
sisted in  French  degras  (sod  oil).  Curriers  in  other  countries 
began  to  imitate  the  French,  and  soon  found  that  they  got  a 
superior  article  of  leather  by  using  French  degras  in  combina- 


232 


THE  MANUFACTURE  OF  LEATHER. 


tion  with  other  greases.  The  method  used  in  France  for 
tanning  oil-dressed  leather,  and  for  making  sod  oil,  differs 
radically  from  that  in  use  in  other  countries.  The  French  pro- 
ceed about  as  follows  :  After  the  usual  beam-house  operations, 
the  skins  intended  for  chamois  leather  are  oiled  on  the  table 
with  fish  or  whale  oil  and  folded  in  cushions.  The  cushions 
are  now  subjected  to  the  action  of  the  fulling  mill  for  an  hour 
or  two,  then  hung  out  in  the  open  air  to  cool  off,  from  one-half 
to  one  hour,  and  after  piling  in  a  heap  for  a  few  hours  they  are 
again  fulled.  These  operations  are  repeated  for  several  weeks, 
giving  the  skins  an  occasional  oiling  off  between  the  fullings. 
After  being  completely  tawed  the  skins  are  generally  soaked  in 
fish  oil  for  a  short  time  and  then  put  in  presses  to  squeeze  out 
the  surplus  oil  that  has  not  chemically  combined  with  the 
fibre.  This  surplus  oil  constitutes  genuine  French  degras. 
If  the  production  of  French  degras  be  the  main  object,  poor 
skins  are  taken  and  the  above  process  of  fulling,  etc.,  and 
pressing  out  the  oil  or  degras,  is  repeated.  Thereby  a  second, 
third,  etc.,  quality  of  degras  is  produced.  In  fact  there  are  a 
number  of  establishments  in  France  and  Austria  that  do  not 
produce  any  oil-dressed  leather,  but  which  manufacture  only 
French  degras.  These  factories  use  only  poor  skins  and  offal 
and  keep  on  tawing  the  same  and  pressing  out  the  degras, 
until  only  a  few  shreds  and  fibres  are  left  of  the  skins.  Genu- 
ine French  degras  has  the  appearance  of  thick  oil  and  is 
perfectly  liquid,  so  that  it  can  be  poured  from  one  bottle  to 
another  with  ease.  It  contains  no  product  of  saponifica- 
tion or  alkali  of  any  kind.  In  speaking  of  the  different  pro- 
cesses of  oil-dressing  we  shall  call  that  used  in  most  European 
countries,  except  France,  simply  the  European.  The  process 
generally  used  in  this  country  and  that  used  in  Europe,  differs 
radically  from  that  in  use  by  the  French.  In  the  American, 
as  well  as  the  European,  process  of  oil-dressing  the  skins  go 
through  a  heating  process,  which  heating  changes  the  sod  oil 
in  the  skins  from  a  thin  fluid  oil  to  a  thick,  viscous  mass.  In 
this  country  the  skins,  after  leaving  the  beam-house,  are  oiled 


STUFFING  LEATHER. 


233 


off  and  then  milled  for  about  an  hour  and  hung  up  for  a  short 
time  to  cool,  and  then  milled  again,  etc.,  as  in  the  French  pro- 
cess. After  being  completely  tawed  they  are  hung  in  a  hot 
room  until  they  are  thoroughly  heated  and  completely  dry* 
and  are  put  through  a  last  milling  and  heating  process  called 
"milling  off."  During  this  "milling  off"  the  skins  become 
very  hot,  and  care  must  be  taken  that  they  do  not  scorch. 

The  European  method  of  oil-dressing  is  again  different  from 
the  American  and  French  processes.  In  the  European  process 
of  chamoising  the  skins,  after  leaving  the  beam-house,  they  are 
oiled  off,  and  three  to  four  skins  made  into  a  cushion,  and 
these  cushions  are  milled  for  three  to  four  hours.  After  oiling 
off  they  are  again  milled,  and  after  getting  a  third  oiling  they 
receive  another  milling;  after  which  they  are  hung  in  the  air  a 
short  time  to  evaporate  a  part  of  the  moisture  in  the  skins,  and 
the  process  of  oiling  and  milling  is  then  continued.  Sheep-skins 
require  six  to  eight  oilings  and  millings  to  be  completely  tawed  ; 
hides  ten  to  twelve.  After  being  sufficiently  tawed,  the  skins  are 
put  through  a  heating  much  more  intense  than  is  customary  in 
this  country.  The  heating  or  fermentation  causes  the  oil  to  oxi- 
dize and  thicken.  Consequently,  the  longer  and  more  intense 
the  heating  is  conducted  the  thicker  and  more  viscous  will  be 
the  resulting  sod  oil.  Thus  we  find  the  genuine  French  sod  oil 
fluid.  The  American  is  so  thick  that  it  cannot  be  poured  from 
one  vessel  into  another,  and  the  European  sod  oil  is  a  mass 
almost  as  thick  as  dough.  In  their  specific  action  on  leather 
there  seems  to  be  very  little  difference.  We  would  remark  that 
the  description  of  the  properties  of  the  different  sod  oils  per- 
tains only  to  natural  sod  oils  made  according  to  the  processes 
as  described,  and  not  adulterated  with  foreign  oils.  Owing  to 
this  difference  in  their  physical  properties,  the  American  and 
European  sod  oils  are  recovered  from  the  oil-dressed  leather  by 
washing  with  an  alkali  solution  and  decomposition  of  the  fat 
liquor  with  sulphuric  acid ;  while  the  French  sod  oil  is  recov- 
ered by  simply  pressing  or  wringing  out  the  surplus  oil.  It 
would  be  found  a  very  tedious  job  to  make  sod  oil  in  this  coun- 


234 


THE  MANUFACTURE  OF  LEATHER. 


try  by  simply  pressing  the  oil  out  of  the  leather,  owing  to  its 
heavy  body.  It  was,  until  recently,  believed  that  the  fish  oil 
used  in  oil  dressing  was  changed  to  sod  oil  by  oxidation.  This 
the  ory  seemed  very  plausible  for  several  reasons.  Heat  is 
always  liberated  by  milling  with  oil,  and  the  only  properties  of 
genuine  sod  oil  that  were  generally  known,  viz. :  the  specific 
odor  and  the  property  of  not  gumming  with  water,  could  be 
given  to  fish  oil  by  artificial  oxidation.  But  the  most  valuable 
and  characteristic  property  of  genuine  sod  oil  has  never  yet 
been  produced  artificially,  and  this  property  is  the  tanning 
principle  of  pure  sod  oil.  Pure  sod  oil  contains  from  15  to  20 
per  cent,  of  a  substance  that  will  chemically  unite  with  the  fibre 
of  partially  tanned  leather,  or  with  raw  hide  which  is  stuffed 
with  it.  This  substance,  when  separated  from  sod  oil,  is  a 
dark  brown,  brittle  body,  resembling  in  its  appearance  dry 
hemlock  extract.  The  tanning  principle  of  pure  sod  oil  is  the 
cause  of  the  high  esteem  in  which  it  is  held  as  a  leather  stuff- 
ing ;  and  there  is  no  doubt  that  it  is  this  substance  that  gives 
to  sod  oil  different  properties  from  the  ordinary  oils  and 
greases,  making  it  so  valuable  to  the  currier.  Therefore,  arti- 
ficial sod  oil,  if  of  good  quality,  while  possessing  some  valuable 
properties  lacks  the  most  important  one  of  natural  sod  oil. 
The  tanning  principle  present  in  natural  sod  oil  effects  a  re- 
tanning  process  in  leather  stuffed  with  it,  at  the  same  time 
imparting  to  it  that  velvety  feel  peculiar  to  leather  stuffed  with 
natural  sod  oil.  If,  therefore,  leather  which  is  not  sufficiently 
tanned,  be  stuffed  with  grease  containing  a  percentage  of  real 
sod  oil,  it  will  undergo  a  retanning,  and  a  nice  mellow  product 
will  be  obtained,  which,  otherwise,  would  not  have  been  the 
case.  Besides  real  sod  oil,  the  only  oils  or  grease  known  which 
contain  a  small  percentage  of  this  tanning  principle,  are  the 
fish  oils. 

Menhaden  Bank  and  Straits  oils  contain  usually  about  one 
to  five  per  cent,  of  tanning  principle.  One  sample  of  genuine 
cod  oil,  which,  by  the  way,  is  a  very  scarce  article,  contained 
seven  per  cent,  of  tanning  principle,  while  other  samples  of  so- 


STUFFING  LEATHER. 


235 


called  cod  oil,  analyzed  by  us,  did  not  show  much  more  than 
Menhaden  Bank  or  Straits  oil.  The  value  of  fish  or  cod  oil  as 
a  leather  lubricant  is  largely  dependent  on  the  amount  of  tan- 
ning principle  contained  therein,  and  an  oil  containing  eight 
per  cent,  of  this  substance  is  really  cheaper  at  thirty-two  cents 
than  another  oil  with  one  per  cent,  tanning  principle  would  be 
at  twenty-three  cents.  Again,  very  many  cheap  fish  oils  may 
be  better  suited  for  oiling  and  chamoising  leather  than  a  high 
priced  cod  oil.  We  have  tested  a  number  of  samples  of  cod  oil 
that  did  not  contain  more  than  one  and  a  half  per  cent,  of  tan- 
ning principle.  Another  point  of  interest  is  the  fact  that  fish 
oils,  rich  in  tanning  principle,  are  much  less  liable  to  "gum" 
than  those  which  contain  a  smaller  percentage  of  this  substance. 
More  than  one-half  the  sod  oils  sold  in  this  country  are  either 
wholly  artificial  or  they  contain  but  a  small  percentage  of 
natural  sod  oil,  and  do  not  contain  more  than  two  to  five  per 
cent,  of  tanning  principle.  We  therefore  claim  that  about  the 
same  results  could  be  obtained  if  a  good  fish  oil  was  substituted 
for  such  artificial  sod  oil  for  stuffing  leather. 

PARAFFIN  WAX. 

Paraffin  wax  is  a  mineral  product  destined  to  largely  displace 
tallow  and  oleo-stearine  in  the  manufacture  of  wax  upper  kids, 
calf  skins,  oil  grains  and  harness  leather. 

It  is  but  a  few  years  since  paraffin  wax,  a  by-product  of 
paraffin  oil,  was  introduced  as  a  substitute  for  tallow,  oleo- 
stearine  and  other  heavy  greases,  in  the  manufacture  of  leather. 
Like  all  innovations,  it  met  with  decided  opposition  from  tan- 
ners educated  to  the  belief  that  animal  greases  are  the  only 
suitable  ingredients  for  "stuffing,"  or  filling  the  pores  and  cells 
of  leather,  thereby  rendering  the  fabric  practically  waterproof, 
as  well  as  producing  that  supple  and  greasy  finish  so  desirable 
for  the  boot,  shoe  and  harness  manufacture. 

Paraffin  wax  has  all  the  filling  properties  of  oleo-stearine, 
together  with  other  good  qualities  of  its  own.  It  will  not 
evaporate  by  long  use ;  it  will  not  dry  or  gum  by  exposure  to 


236 


THE  MANUFACTURE  OF  LEATHER. 


the  inclemency  of  the  weather,  and  it  can  be  melted  at  a 
temperature  of  124  to  126  degrees  F.,  in  connection  with  tallow 
or  degras.  At  this  temperature  the  greases  are  readily  ab- 
sorbed, if  the  stuffing  wheel  is  employed.  Indeed,  the  stuffing 
wheel  is  the  only  practical  method  of  forcing  heavy  greases 
into  the  pores  and  cells  of  leather.  As  the  tanners  become 
more  conversant  with  the  filling  and  preserving  properties  of 
paraffin  wax,  they  will  be  averse  to  paying  for  oleo-stearine, 
when  the  wax  will  give  equal  satisfaction,  and  at  a  lower  cost. 

Tanners,  as  a  rule,  are  slow  to  adopt  or  even  experiment 
with  new  materials,  but  within  the  past  year,  and  largely  due  to 
the  almost  prohibitive  prices  of  oleo-stearine,  paraffin  wax  has 
been  successfully  introduced.  We  learn  that  it  is  securing  a 
strong  foothold  in  many  tanneries.  Where  it  has  been  ac- 
corded a  fair  trial,  satisfactory  results  have  followed,  and  there 
have  at  times  been  duplicate  orders  for  car  lots. 

A  tanner  who  keeps  pace  with  the  times  must  be  constantly 
on  the  alert  to  secure  tanning  and  finishing  materials  on  a  basis 
that  will  allow  him  to  successfully  compete  with  his  neighbor, 
and  without  in  the  least  deteriorating  the  quality  of  his  pro- 
duce. It  has  become  necessary  to  look  for  economical  sub- 
stitutes for  bark,  oils,  tallow,  and,  indeed,  for  all  that  enters  into 
the  leather  manufacture.  Oleo-stearine  when  first  introduced 
to  tanners  was  regarded  with  suspicion,  because  of  the  belief 
that  all  the  best  properties  were  extracted  in  the  manufacture 
of  butterine.  The  tanners  have  since  learned  that  they  cannot 
do  without  it,  especially  in  warm  weather,  and  the  same  may 
be  said  of  the  compounders  of  lard. 

GLYCERINE. 

The  introduction  of  mineral  salts  in  the  manufacture  of 
leather  created  many  changes  in  the  trade,  and  almost  revolu- 
tionized the  methods  then  in  use  for  currying  and  finishing; 
many  ingredients  hitherto  unknown  were  brought  forward, 
amongst  which  was  glycerine. 

This  article  now  takes  a  very  prominent  part,  and  that  part 


STUFFING  LEATHER. 


237 


is  after  tannage  to  relieve  the  tension  of  the  fibre  of  the  stock, 
so  as  to  take  what  other  ingredients  may  be  required  to  make 
it  perfect  leather,  and  at  the  same  time  to  impart  a  feel  to  the 
leather  that  cannot  be  produced  with  any  other  fatty  matter. 
It  may  be  of  interest  to  know  how  this  article  is  produced.  It 
is  a  liquid  obtained  by  the  decomposition  of  fats  and  fixed  oils, 
and  containing  not  less  than  95  per  cent,  of  absolute  glycerine, 
a  sweet  principle,  obtained  from  fats  and  fixed  oils  and  con- 
taining a  small  percentage  of  water.  It  is  a  clear,  colorless 
liquid  of  syrupy  consistence,  oily  to  the  touch,  hygroscopic, 
without  odor,  very  sweet  and  slightly  warm  to  the  taste,  and 
neutral  in  reaction.  It  is  soluble  in  all  proportions  in  water 
and  in  alcohol,  also  in  a  mixture  of  3  parts  of  alcohol  and  1 
part  of  ether,  but  insoluble  in  ether  alone  or  chloroform,  benzol, 
or  fixed  oils.  In  proportions  glycerine  is  intermediate  between 
water  and  the  oil ;  when  exposed  to  the  air  it  gradually  absorbs 
moisture.  Glycerine  possesses  great  powers  as  a  solvent,  es- 
pecially those  of  the  chlorides  of  potassium  and  sodium  of  the 
alkaline  earths.  It  also  dissolves  the  vegetable  acids,  and  par- 
ticularly tannic  acid.  It  is  known  that  certain  neutral  vegetable 
substances  are  far  more  soluble  in  glycerine  than  in  water. 
Glycerine  does  not  evaporate  when  exposed  to  the  air,  nor  can 
it  be  distilled  without  decomposition  unless  in  the  presence  of 
water  or  steam.  Pure  glycerine  is  very  essential  where  it  is  to 
be  used  on  leather,  and  these  precautions  should  be  taken. 

See  that  its  consistency  is  up  to  standard,  and  that  it  is 
neutral  (this  can  be  ascertained  by  litmus  paper).  C.  P.White 
30   is  generally  used,  and  is  by  far  the  safest  to  buy. 

From  the  time  that  the  special  property  of  glycerine  of 
softening  leather  and  rendering  it  supple  became  known,  it  has 
largely  been  used  for  oiling  in  the  place  of  fat  or  degras. 
Although  glycerine  is  capable  of  imparting  to  leather  a  high 
degree  of  softness  and  suppleness,  it  is  incorrect  to  credit  it 
with  actual  preserving  properties.  It  is  equally  wrong  to  re- 
gard the  suppleness  it  imparts  to  leather  as  a  direct  nourish- 
ment and  strengthening.    In  this  respect  glycerine  does  not 


238 


THE  MANUFACTURE  OF  LEATHER. 


replace  the  fats,  which  may  be  considered  as  direct  nourishers 
of  the  leather,  while  the  former,  in  spite  of  suppleness  it  im- 
parts, also  possesses  a  certain  corroding,  lixiviating  alkaline 
effect.  For  this  reason,  glycerine,  though  advantageous  its 
direct  effect  may  be,  should  never  be  used  alone  for  oiling  and 
softening  leather,  the  more  so  as  wet  and  humidity  will  readily 
wash  it  out,  whereby  its  influence  is  rendered  nil ;  besides  this, 
when  the  glycerine  is  expelled  it  also  carries  away  certain  soft- 
ening constituents  of  the  leather  itself,  which  had  partly  be- 
come dissolved  in  the  glycerine,  thereby  leaving  a  leather  that 
has  become  to  that  extent  harder.  This  is  the  more  worthy 
of  attention,  as  it  is  quite  frequent  that  glycerine  rubbed  into 
leather  is  expelled  from  it  by  the  influence  of  wet ;  and  although 
the  use  of  this  unguent  has  become  a  custom  everywhere,  the 
currier  should  avoid  using  it  alone  for  oiling  leather,  but  mix  it 
previously  with  supplementary  ingredients — in  other  words, 
prepare  it  first  in  a  corresponding  manner. 

Glycerine  of  itself  is  wanting  in  the  proper  power  of  binding 
it  to  the  leather,  which  is  due  to  its  exceedingly  great  solu- 
bility in  water.  Attempts  were  formerly  made  in  practice  to 
correct  this  want  by  previously  rubbing  the  leather  slightly 
with  glycerine,  and  then,  as  it  were,  giving  it  a  more  substantial 
covering  of  melted  tallow,  but  in  this  procedure  the  effect  of 
the  glycerine  was  only  small  and  simply  of  a  secondary  nature. 
In  order  to  correct  the  want  of  the  binding  power  of  glycerine, 
if  not  wholly  at  least  largely,  the  currier  must  seek  to  princi- 
pally neutralize  its  very  great  solubility  in  water.  This  can 
naturally  not  be  done  altogether  without  partially  changing  the 
nature  of  glycerine,  and  of  course,  also  its  softening  effects. 
Still  a  better  adherence  of  the  glycerine  to  the  leather  can  be 
brought  about  thereby. 

This  may  be  effected  in  two  ways.  According  to  one,  and 
doubtless  the  most  practical  way,  a  kind  of  artificial  degras  is 
composed  with  glycerine,  by  emulsioning  it  in  a  strong  concen- 
tration, therefore  as  a  very  viscid  substance  with  fatty  bodies. 
As  glycerine  acts  in  a  certain  sense  as  a  feeble  alkali,  similar  to 


STUFFING  LEATHER. 


239 


a  solution  of  potash,  with  which  the  degras  is  extracted  from 
morocco-tanned  skins,  it  can  readily  be  rubbed  together  with  a 
mixture  of  fish-oil  and  beef  tallow,  and  emulsioned  with  it. 
The  desired  quantity  of  beef  tallow  is  first  dissolved  in  heated 
fish-oil,  the  mixture  is  well  stirred  together  and  permitted  to 
congeal  to  a  butter-like  consistency.  To  the  soft  mixture  of 
fats  is  then  added  about  one-quarter  of  its  weight  of  glycerine, 
and  intimately  incorporated  with  it,  so  that  the  mass  is  finally 
of  a  cream-like  condition.  This  glycero-degras  enables  the 
currier  to  obtain  the  same  advantages  as  from  lubricating  with 
fat  or  glycerine  alone. 

Glycerine  may  also  be  fixed  in  the  leather  by  preparing  it 
with  substances  which  will  dry  out,  and  thereby  lose  their  solu- 
bility in  part,  and,  of  course,  neutralize  this  in  a  measure  in  the 
glycerine.  For  this  purpose  it  might  be  recommended  to  mix 
glycerine  with  egg  albumen,  rubbing  together,  but  always  in 
such  a  proportion  that  the  latter  is  present  only  in  a  very  small 
quantity.  This  imparts  to  the  non-drying  glycerine  a  certain 
fixing  basis,  which  again  thereby  preserves  its  greatest  virtue 
of  imparting  suppleness.  This  prepared  albuminous  glycerine 
may  either  be  used  alone,  or  else  serve  as  basis  for  the  previ- 
ously-mentioned glycero-degras. 

In  cases  when  such  a  trifling  addition  of  albumen  should 
appear  too  costly,  glycerine  may  also  be  mixed  with  a  small 
quantity  of  dextrine  solution — an  addition  that  is  decidedly  a 
defective  one,  still  it  answers  its  purpose  to  a  certain  extent. 

The  combination  of  glycerine  with  tannin  may  also  be  re- 
garded as  a  special  preparation.  A  corresponding  quantity  of 
extract  of  oak-bark  or  other  tannin  is  by  boiling  dissolved  in 
glycerine,  which  is  easily  done,  and  in  this  way  it  becomes  a 
very  valuable  fat  for  lubricating  the  hide  ;  the  good  effects  being 
still  increased  by  emulsioning  this  tanninous  glycerine  in  the 
above-explained  manner  with  fish  oil  and  tallow,  and  converting 
it  into  a  degras. 

A  practical  method  of  stuffing  with  glycerine  is  described  as 
follows :  The  leather  is  treated  with  a  mixture  of  tallow,  degras 


240 


THE  MANUFACTURE  OF  LEATHER. 


or  fish- oil,  and  glycerine,  instead  of  with  the  ordinary  stuffing 
grease.  As  glycerine  combines  well  with  water,  the  stuffing  is 
readily  absorbed,  and  the  glycerine  very  evenly  distributed, 
which  not  only  adds  substance,  but  makes  the  leather  excep- 
tionally soft.  After  the  leather  has  been  blackened,  and  while 
only  partially  dry,  glycerine  may  again  be  worked  into  the 
grain  side,  followed  by  a  coating  of  wax ;  this  prevents  the 
glycerine  from  working  out  on  the  surface  and  gives  a  drier 
feel.  The  method  described  gives  a  pleasing  dull  lustre  to  the 
leather. 

From  the  preceding  it  will  be  seen  that  although  glycerine 
possesses  certain  advantages,  it  has  also  great  defects,  which 
can  be  corrected  only  by  suitable  preparation  and  admixture 
of  other  substances. 

TESTING  OILS. 

Oils,  degras,  grease,  etc.,  are  difficult  to  judge,  as  to  their 
real  honest  value.  To  those  inexperienced  in  testing  and  tast- 
ing cod  oils,  etc.,  inferior  goods  are  not  much  unlike  the  better 
grades.  And  it  is  well  known  that  excellent  leather  may  be 
spoiled  and  damaged  in  finish  and  appearance  by  the  use  of 
adulterated  materials,  skilfully  compounded  and  sold  at  low 
prices  which  attract  unwary  buyers. 

There  are  few  commodities  sold  in  which  adulteration  is 
practiced  more  than  in  oils,  as  tanners  and  curriers  know  to 
their  cost.    We  suggest  the  following  simple  tests : 

Apart  from  the  test  for  determining  compound  oils,  there 
appears  to  be  no  other  except  a  chemical  test,  and  that  is  un- 
satisfactory. To  determine  the  amount  of  compounding,  take 
a  two-ounce  vial  and  fill  it  half  full  of  a  very  strong  alkaline 
solution — ammonia,  caustic  soda  or  caustic  potash.  Fill  the 
vial  nearly  full  of  oil  and  shake  thoroughly.  Mineral  oil  will 
not  make  soap,  and  will  separate.  Any  animal  or  fish  oil  will 
mix  with  the  alkali,  and  from  its  color  can  be  told  the  com- 
pound and  the  percentage  of  the  same.  Neat's-foot  oil  will  be 
yellow,  but  tallow  and  most  other  oils  will  be  of  different  shades 


STUFFING  LEATHER. 


241 


approaching  white.  Lard  oil  will  be  whiter  than  tallow.  The 
test  will  show  sperm  oil  to  be  composed  of  about  two  thirds  of 
paraffin  oil.  Lard  oil  is  similarly  adulterated.  This  test  does 
not  show  the  "stock"  from  which  the  oil  is  made,  nor  whether 
the  animal  acids  have  been  extracted  from  the  animal  oils. 
These  should  have  the  acids  extracted,  which  honest  oil  dealers 
now  can  do. 

The  evil  effects  of  the  bad  conditions  of  fats  generally  do  not 
show  themselves  until  the  leather  is  finished  and  probably  out 
of  the  hands  of  the  tanner.  The  worst  of  these  defects  is  the 
gumming  and  exudations  due  to  the  excess  of  acids  in  the  oils, 
tallow  or  degras.  The  blame  is  not  always  due  to  the  seller. 
The  free  acids  increase  in  stored  oils,  and  so  it  is  quite  possible 
that  an  oil  which  was  of  very  good  quality  when  bought  may 
become  almost  worthless  from  excess  of  these  acids  by  the 
time  it  is  used.  To  distinguish  a  genuine  degras  from  simple 
fat  emulsions,  the  latter  being  generally  sold  at  a  higher  price 
than  the  former,  chemists  nowadays  generally  resort  to  an  esti- 
mation of  the  degras  former.  The  most  usual  adulteration  was 
found  to  be  cheap  wool  fat,  which  if  present  in  any  quantity 
will  give  leather  liquored  with  it  a  sticky  feeling,  which  is  the 
reason  that  wool  fat  cannot  be  used  in  tanning.  In  tallow  the 
principal  adulterant  found  is  cotton-seed  oil.  Rancid  tallows 
which  spew  out  on  leather  are  frequently  found.* 

*  For  exhaustive  treatises  on  all  the  oils,  the  reader  is  referred  to  the  following 
books : 

Brannt.  Petroleum:  Its  History,  Origin,  Occurrence,  Production,  Physical  and 
Chemical  Constitution,  Technology,  Examination  and  Uses;  together  with  the  Occur- 
rence and  Uses  of  Natural  Gas.  Edited  by  William  T.  Brannt;  Philadelphia,  Henry 
Carey  Baird  &  Co.,  1895.    Price,  $7.50. 

Brannt.  A  Practical  Treatise  on  Animal  and  Vegetable  Fats  and  Oils:  Comprising 
both  Fixed  and  Volatile  Oils,  their  Physical  and  Chemical  Properties  and  Uses,  the 
Manner  of  Extracting  and  Refining  them,  the  Practical  Rules  for  Testing  them;  as 
well  as  the  Manufacture  of  Artificial  Butter  and  Lubricants,  etc.  By  William  T. 
Brannt;  second  edition,  revised,  2  volumes;  Philadelphia,  Henry  Carey  Baird  &  Co., 
1896.  Price,  $10.00. 
16 


242 


THE  MANUFACTURE  OF  LEATHER. 


BORAX. 

Borax,  in  addition  to  being  used  for  softening  water  used  in 
the  soaks,  and  in  the  leaches  for  extracting  tannin,  and  for 
washing  hides  and  skins  previous  to  placing  them  in  the  tan 
liquor,  is  also  employed  for  cutting  the  oils  and  fats  used  in 
stuffing  leathers.  Sal  soda,  chip,  soaps,  and  soapine  and  other 
alkalies  are  also  used  for  the  same  purpose. 

STEAM  JACKET  KE'ITLES. 

E.  B.  Badger  &  Sons,  Boston,  Mass.,  coppersmiths,  manufac- 
ture steam  jacket  kettles  and  copper  work  of  all  kinds  for  the 
tannery  and  currying  shop. 

STUFFING  OR  FAT  LIQUORING  WITH  PALERMO  FIG  SOAP. 

Many  tanners  find  great  difficulty  in  properly  stuffing  or  fat 
liquoring  the  leather  after  it  is  tanned.  This  is  due  to  the  fact 
that  many  people  consider  this  operation  a  comparatively  un- 
important one,  believing  that  if  the  leather  is  properly  tanned 
the  subsequent  processes  will  regulate  themselves  accordingly. 

This  is  a  mistake,  as  the  precipitation  of  fatty  or  oleaginous 
bodies  in  the  fibre  of  the  skin  is  an  operation  requiring  as  much 
judgment,  skill  and  knowledge  of  materials  used  as  any  division 
in  the  complex  art  of  leather  manufacture.  The  great  desider- 
atum in  all  fat  liquors  is  a  soap  which  will  combine  readily  with 
the  other  ingredients  and  enter  into  combination  with  the  min- 
eral salts,  or  tannins  in  the  fibre  of  the  skin,  so  as  to  render  the 
finished  leather  soft,  smooth  and  flexible  without  any  traces  of 
grease  being  left  on  the  surface. 

Of  the  few  soaps  which  possess  this  valuable  property  we 
know  of  none  so  well  adapted  to  the  stuffing  of  all  kinds  of 
grain  leather  as  that  manufactured  by  F.  E.  Atteaux  &  Co.  and 
sold  under  the  name  of  Palermo  Fig  Soap. 

This  soap  contains  in  itself  all  the  properties  of  a  good  fat 
liquor,  being  rich  in  alkali  without  any  excess  of  the  same,  and 
has  the  additional  advantage  of  always  being  ready  for  use; 
thus  dispensing  with  the  labor  of  making  up  a  fresh  supply  of 


STUFFING  LEATHER. 


243 


fat  liquor  for  each  batch  of  skins.  Although  it  can  be  used 
as  a  fat  liquor  without  any  other  ingredient,  it  also  mixes 
readily  with  all  the  animal,  fish  and  vegetable  oils  and  also  with 
egg  yolk,  and  can  be  used  in  conjunction  with  them  in  any  pro- 
portion. 

It  imparts  a  fine,  glossy  finish  to  the  leather  and  fills  up  the 
pores  and  nourishes  the  skin  to  an  extent  that  no  other  soap  or 
fat  liquor  can  equal.  It  dissolves  readily  in  boiling  water  and 
can  be  applied  to  the  skins  at  a  temperature  of  1250  F. 

FORMULA  FOR  MAKING  FAT  LIQUOR  WITH   PALERMO  FIG  SOAP. 

Put  ten  pounds  Palermo  fig  soap  in  a  clean  barrel  with  just 
sufficient  water  to  cover  the  soap.  Apply  steam  and  stir  con- 
stantly, until  the  soap  is  thoroughly  dissolved.  Now  add  to  the 
soap  bath  four  gallons  of  neats'-foot  oil  or  cod  oil  (first  cut  the 
oil  with  a  few  ounces  of  borax,  potash  or  sal  soda).  Stir  for  a  few 
minutes  until  the  oil  and  soap  are  thoroughly  assimilated,  then 
run  in  forty  gallons  of  cold  water  to  cool  the  emulsion.  Then 
add  ten  pounds  egg  yolk  and  two  pounds  common  salt.  Stir 
the  whole  again,  and  apply  to  skins  at  a  temperature  of  750  F. 

Twenty  gallons  of  this  fat  liquor  is  sufficient  to  fat  liquor  ten 
dozen  skins.  It  should  be  added  gradually  to  the  skins,  and 
the  quantity  used  can  be  varied  to  suit  the  tanner's  judgment. 
It  will  give  excellent  results  on  any  description  of  light  upper 
leather  or  glove  stock.  The  proportions  should  be  changed, 
however,  when  it  is  intended  for  use  on  heavy  calf  skins,  in 
which  case  it  would  be  well  to  add  to  the  oil  and  soap  bath  five 
or  six  pounds  of  French  degras,  and  the  amount  of  egg  yolk 
may  be  reduced  to  five  pounds. 

In  all  cases  care  should  be  taken  to  cool  off  the  soap  and  oil 
emulsion  before  adding  the  egg  yolk,  in  order  to  prevent  coag- 
ulation of  the  albuminous  constituents  of  the  egg  which  would 
result  if  the  latter  was  added  to  water  of  a  higher  temperature 
than  750  F. 

FAT  LIQUORS. 

It  is  hard  to  answer  the  query  of  "What  is  the  best  fat 


244 


THE  MANUFACTURE  OK  LEATHER. 


liquor  for  chrome  tanned  leather?"  as  hardly  any  two  manufac- 
turers use  the  same  formula.  All  the  dealers  in  oils  and  fats 
have  a  fat  liquor  of  their  own  make.  The  Martin  Dennis  Chrome 
Tannage  Company,  Newark,  N.  J.,  also  make  and  sell  a  speci- 
ally-prepared fat  liquor,  under  the  name  of  "Chromol."  Some 
manufacturers  have  trouble  in  obtaining  an  even  color  on  their 
skins — as  they  are  spotted  in  places  in  the  color. 

There  are  various  causes  for  this,  but  generally  the  fault  lies 
either  in  the  animal  grease  not  being  taken  out  or  in  too  much 
fat  liquoring.  One  of  the  most  successful  tanners,  whose  leather 
always  shows  a  superior  face  and  grain,  sends  all  his  skins  after 
being  blacked  to  a  concern  who  take  out  grease  by  the  naphtha 
process.  Some  manufacturers  use  a  bath  of  water  and  borax 
for  the  same  purpose.  On  receiving  them  back  they  are  staked 
and  recolored. 

CHROMOL  FAT  LIQUOR  FOR  CHROME  TANNED  LEATHER  DIRECTIONS  FOR  USE. 

Chromol  may  be  warmed  as  it  is  and  used  as  a  hand  stuffing 
for  heavy  leather ;  or  may  be  dissolved  in  any  proportion  of 
warm  water  and  used  as  a  fat  liquor,  and  milled  into  the  leather 
by  means  of  a  pin  mill  drum. 

Chromol  imparts  great  softness,  pliability  and  strength  to 
the  chrome  leather  without  rendering  the  leather  in  the  least 
greasy  or  gummy. 

One  special  and  desirable  feature  of  this  preparation  is  that 
it  may  be  used  on  all  fancy  light  colors  without  spotting  or 
streaking  the  leather,  a  fact  which  commends  it  as  a  substitute 
for  egg  yolk. 

For  glove  leather  it  is  sometimes  desirable  to  make  a  batter 
of  flour  and  water  and  then  add  the  chromol  to  the  batter,  and 
knead  or  mill  the  skins  in  the  mixture. 

WATER-PROOF  STUFFING. 

A  good  water-proof  stuffing  can  be  made  as  follows :  Two 
and  one  half  ounces  of  good  drop  black  or  vegetable  black  well 
ground  in  any  suitable  oil,  ten  ounces  of  castor  oil,  French  sec- 
ond pressing,  and  eight  ounces  of  tallow. 


STUFFING  LEATHER. 


245 


WATER-PROOFING  LEATHER. 

The  process  of  rendering  leathers  water-proof,  or  impene- 
trable to  water,  has  formed  the  subject  of  many  patents ;  but 
with  the  exception  of  rendering  leather  impervious  to  water  by 
the  aid  of  mineral  salts,  we  have  not  met  with  any  compound 
that  perfectly  water-proofs  leather,  whether  upper  or  sole,  ex- 
cept the  following : 

As  regards  the  mineral  process,  the  formation  of  sebate  of 
alumina  or  of  iron  in  the  leather,  by  first  steeping  the  leather 
in  a  solution  of  soap  and  then  in  one  of  either  of  the  above 
salts,  has  never  yet  proved  its  full  title  to  be  a  perfect  water- 
proofing process ;  and  also  the  process  of  rendering  gelatine 
insoluble  in  the  pores  of  leather  by  means  of  an  astringent,  as 
alum,  does  not  perfectly  fulfill  all  the  conditions  necessary  for 
rendering  the  leather  so  treated  impervious. 

As  regards  stuffing  componds,  which  depend  for  their  effic- 
iency in  filling  the  pores  with  some  body,  such  as  resin  or  wax, 
antagonistic  to  water,  those  compounds  are  far  from  good,  be- 
cause those  of  such  compounds  that  cannot  be  extracted  from 
the  leather  by  heat  may  be  eliminated  by  means  of  alkalies, 
which,  by  saponification  of  the  resin  or  wax,  render  these  bod- 
ies miscible  in  water.  Compounds  in  which  resin  is  the  solid 
compound  for  filling  up  the  pores  of  the  leather  to  make  it 
water-repellent  can  be  converted  into  a  miscible  compound  by 
means  of  sodic  hydrate,  while  those  compounds  which  depend 
for  these  water-proofing  qualities  on  the  wax  as  a  component 
can  be  similarly  treated  by  means  of  borax  or  borax  and  am- 
monia. 

One  of  the  most  favorite  compounds  for  giving  leather  the 
quality  of  water-resisting  is  paraffin  wax,  either  driven  into  the 
leather  by  means  of  heat,  or  else  by  means  of  a  solvent,  as 
naphtha,  benzine  or  carbon  disulphide.  But  this  wax  can  also 
be  extracted  again  from  the  leather  by  either  of  these  means  ; 
and  if  it  be  upper  leather  thus  water-proofed,  the  lining  of  the 
boot  made  therefrom  will  become  saturated  with  the  wax  if  the 
boot  be  held  in  front  of  a  fire  ;  and  again,  if  a  spontaneous 


246 


THE  MANUFACTURE  OF  LEATHER. 


solution  of  this  or  any  other  wax  be  used  to  impregnate  sole 
leather,  the  wax  will  be  eventually  driven  out  of  it  by  the  pres- 
sure on  the  sole  when  the  leather  is  made  up  into  boots. 

After  trying  some  scores  of  formulae  for  producing  water- 
proof leather,  we  can  find  nothing  better  than  these  two.  For 
sole  leather:  Warm  the  leather  if  it  is  oak  or  hemlock  tanned 
and  heat  it  if  it  is  mineral  tanned  and  brush  it  with  a  coat  of 
copal  or  amber  varnish ;  an  oil  varnish  is  better  than  a  spirit 
varnish,  as  the  former  is  more  flexible,  while  for  upper  leather 
nothing  is  superior  to  this  compound  : 

1  part  by  weight  of  raw  gutta  percha, 

1  part  by  weight  of  paraffin  wax, 

2  to  3  parts  by  weight  of  benzine. 

The  gutta  percha  should  be  the  raw,  brown  kind,  not  the  vul- 
canized or  colored  kind. 

To  make  this  mixture,  put  the  ingredients  into  a  jar  lightly 
covered  with  a  plate  and  place  this  vessel  near  some  source  of 
heat  where  it  will  be  very  gradually  raised  to  a  warm  tempera- 
ture, but  not  enough  to  cause  the  benzine  to  vaporize,  ignite  or 
explode.  Be  very  careful  about  explosions.  After  the  solids 
have  dissolved,  stir  the  mixture  and  then,  having  rendered  the 
leather  warm,  brush  it  with  this  solution,  or  else  steep  the 
leather  therein  until  well  impregnated,  and  then  hang  up  to 
dry. 

The  compound,  if  properly  prepared,  will  set  semi-solid,  and 
only  requires  to  be  reheated  for  use  as  above. 

The  advantage  of  this  compound  is  this:  Both  the  wax  and 
gutta  percha  enter  the  pores  of  the  leather  in  a  finely-divided 
state  and  fill  them  up,  while  the  volatile  solvent  eventually 
evaporates  out  of  the  leather,  leaving  the  solids  therein ;  now, 
neither  of  these  bodies,  wax  or  gutta  percha,  can  be  completely 
eliminated  from  the  pores  of  the  leather,  because  they  are  so 
thoroughly  combined  and  in  such  a  fine  state  that  an  alkali 
would  fail  to  saponify  the  wax,  and  heat  would  fail  to  drive  it 
out,  because  the  gutta  percha  is  worked  in  by  the  alkali,  and 


STUFFING  LEATHER. 


247 


being  so  intimately  impregnated  in  the  pores,  it  is  next  to  im- 
possible to  drive  it  out  by  heat ;  moreover,  the  gutta  percha  is 
a  flexible  body.  And  then  this  mass  is  an  excellent  stuffing 
compound  for  curriers'  use  in  preparing  water-proofed  wax 
calf,  satin  hide,  pebble  grain,  etc. 
The  author  of  the  above  says : 

"  I  have  tried  this  water-proofing  compound  on  a  score  of 
different  kinds  of  leather,  and  never  found  it  to  fail  in  rendering 
them  absolutely  impervious  to  water  ;  and,  moreover,  so  water- 
repellent  that  the  leather  will  float  in  water  for  hours,  sufficient 
proof  that  no  water  enters  the  pores  ;  both  these  solid  bodies 
are  unacted  on  by  alkalies,  and  thus  I  believe  I  can  claim  for 
this  compound  (one,  by  the  way,  which  I  have  formulated  after 
much  research)  the  quality  of  being  a  perfect  water-proofing 
compound. 

"As  regards  colored  leathers — tan,  morocco,  etc. — I  advise 
one  application  only  applied  to  the  flesh  side  lightly,  not  suf- 
ficient to  stain  the  leather  through  ;  but  for  upper  leathers  (kid 
excepted),  the  leather  may  be  steeped  in  the  compound,  and 
wiped  free  of  all  superfluous  drippings." 


CHAPTER  XVI. 


SETTING- OUT. 

THE  method  of  setting-out  described  in  the  preceding  chap- 
ter is  not  suitable  for  all  classes  of  leather,  but  is  for  kips 
and  skins  or  other  light  leather.  Heavy  leathers,  such  as 
harness  and  belting  leathers,  require  a  considerable  amount  of 
labor  in  setting,  and  it  must  be  done  in  suitable  condition  if  it 
is  to  be  properly  done.  When  available,  the  setting  machine 
may  be  successfully  used  if  skilfully  applied,  but  in  applying 
the  same  care  must  be  taken  not  to  distort  the  pattern  of  the 
hide,  otherwise  it  will  take  the  men  who  reset  after  the  machine 
as  long  to  regain  a  good  pattern  as  the  machine  has  saved ; 
nevertheless,  as  above  said,  if  the  machine  is  skilfully  applied  it 
may  be  advantageously  used  in  doing  the  most  laborious  part 
of  the  work. 

The  machine  shown  in  Fig.  61  is  built  by  the  Vaughn 
Machine  Company,  Peabody,  Mass.,  and 'is  for  stoning-out, 
scouring  and  setting-out,  and  is  intended  to  be  used  for  glove, 
satin  and  oil  grain,  wax  and  split  leathers,  etc. 

This  machine  will  remove  the  wrinkles  from  the  neck,  and 
will  in  every  way  smooth  out  and  thoroughly  prepare  the 
side  or  hide  for  the  belt  knife  leather-splitting  machine. 
In  fact  it  is  invaluable  for  stoning-out  rough  leather  for  the 
leather-splitting  machine,  and  far  better  results  are  obtained 
with  it  than  can  be  had  in  any  other  way.  The  machines 
shown  in  Figs.  39  and  83  are  also  used  for  stoning-out ;  but 
the  machine  shown  in  Fig.  61  is  used  for  large  products  of 
leather. 

(  248) 


SETTING-OUT. 


249 


CHAPTER  XVII. 


WHITENING  AND  SHAVING  LEATHER. 


Fig.  62. 


The  side  having  been  stufifed  and  next  "  set  out "  (which 
latter  operation  can  be  performed  for  calf-skins  or  the  heavier 
grades  of  upper  leather  by  the  machines  shown  in  Figs.  58,  59 
and  60),  the  next  step  in  the  pro- 
cess of  manufacturing  upper  leather 
is  that  of  whitening.  This  is  usually 
accomplished  by  one  of  three  ways  : 
The  leather  may  be  placed  on  a 
table  and  whitened  with  a  slicker,  or 
cut  over  with  a  currier's  knife  on  a 
beam,  or  the  whitening  can  be  per- 
formed by  machinery. 

Fig.  62  shows  the  French  pattern  of  whitening  slicker,  which 
is  the  kind  usually  employed  in  this  country.  The  blades, 
which  are  of  cast  steel,  are  usually  of  two  degrees  of  hardness ; 
the  bright  blade  compares  in  temper  with  a  medium  hard  blade, 
the  half  polished  are  softer,  being  of  a  lower  temper. 

Fig.  63  shows  the  form  of  beam  now  generally  employed  in 
currying  shops.  The  beam-bed  and  face  are  adjustable  by 
means  of  screws,  and  the  beam  may  be  elevated  or  lowered  at 
any  necessary  height  to  suit  the  convenience  and  comfort  of  the 
workman.    The  faces  may  be  either  6f  lignum  vita;  or  of  glass. 

There  is  a  great  variety  in  the  construction  of  currier's 
knives ;  but  the  form  shown  in  Fig.  64  is  the  most  common. 
The  blades  are  screwed  in  the  brass  jaws  by  three  screws  from 
each  side,  thus  securing  equal  strength.  The  blades  for  the 
currier's  knives  are  made  of  hammered  steel,  and  are  either 
bright  or  unpolished,  and  vary  from  seven-eighths  to  two  inches 

(  250) 


WHITENING  AND  SHAVING  LEATHER.  25  I 

Fig.  63. 


in  width,  and  those  kept  in  stock  by  the  manufacturers  are 
made  in  nineteen  and  twenty  gauge,  but  other  gauges  are 
manufactured  to  order. 

UNION  WHITENING  AND  BUFFING  MACHINE. 

The  Union  Whitening  and  Buffing  Machine,  made  by  J.  T. 
Freeman  &  Co.,  Woburn,  Mass.,  is  based  upon  the  patents 
granted  to  Oliver  C.  Smith,  of  Ipswich,  Mass.,  several  later 
patents  having  been  granted  to  J.  T.  Freeman  et  al.  for  improve- 
ments. 


252 


THE  MANUFACTURE  OF  LEATHER. 


The  machine  for  whitening  and  buffing  leather  invented  by 
Oliver  C.  Smith  is  shown  in  Figs.  65  to  68. 


Fig.  66. 


Fig.  67. 


1     22  ' 

Figure  65  represents,  in  top  view,  a  machine  embodyiug 
Smith's  invention ;   Fig.  66,   a  longitudinal  vertical  section 


WHITENING  AND  SHAVING  LEATHER. 


253 


thereof  on  the  dotted  line  x  x,  the  table  or  bed  being  shown  in 
elevation.    Fig.  67  is  an  enlarged  detail, 
partially  in  section,  showing  the  boxes  of  Fig.  68. 

the  sliding  frame;  and  Fig.  68,  a  section 
of  Fig.  67  on  the  dotted  line_y_y. 

In  this  invention  the  pulley  A  is  fixed  9 
directly  upon  the  crank-pin  //,  joining  the 
two  cranks  i  k,  projected  from  the  shaft 
B.  The  weight  of  the  pulley  A  is  coun- 
terbalanced by  the  weight  C,  one  on  each 
crank.  The  belt  11  on  this  large  fixed  pulley  A  is  extended 
over  the  pulley  t  on  the  shaft  a2  at  the  upper  end  of  the  usual 
swinging  frame,  and  rotates  the  said  shaft,  together  with  its 
pulleys  s,  which  by  small  belts  r  revolve  the  rotary  cylinder  or 
tool  p  in  the  usual  manner  as  the  link  g,  herein  made  double, 
reciprocates  the  carriage  D  on  the  guide-rods  c.  This  carriage 
is  composed  of  yokes  20,  21,  connected  by  a  bar,  22,  the  yokes 
having  depending  from  them  bearings  a3  to  receive  the  shaft  a2, 
which  turns  in  the  said  bearings.  The  boxes  which  run  on  the 
guide-rods  c  have  Babbitt  or  other  linings,  E  F.  Upon  the  lin- 
ing F,  the  inventor  has  placed  an  adjusting-wedge,  G,  provided 
with  one  or  more  inclined  teeth  or  wedging-surfaces,  9,  and 
above  the  adjusting-wedge  he  has  placed  a  cap,  /,  having  at  its 
under  side  one  or  more  opposed  teeth  or  inclines,  8. 

The  machine,  as  at  present  built  by  J.  T.  Freeman  &  Co.,  of 
Woburn,  Mass.,  is  shown  in  Fig.  69. 

This  is  the  only  machine  ever  put  on  the  market  that  will 
whiten  and  buff  successfully.  It  works  the  same  on  stuffed, 
greased  or  dry  leather.  It  does  the  work  equally  as  well  as  can 
be  done  by  hand  and  takes  off  no  more  stock.  It  turns  off  a 
large  amount  of  work  and  requires  but  a  short  time  for  an 
operator  to  learn  to  run  it.  Since  purchasing  the  patents  and 
patterns  of  the  above  machine  J.  T.  Freeman  &  Co.  have  made 
a  large  reduction  in  the  selling  price  of  it  and  have  placed  it  at 
a  figure  in  reach  of  all  leather  manufacturers,  in  fact  where 
they  cannot  afford  to  be  without  them.  The  machine  occupies 
a  space  of  about  10x5  ft.  and  is  driven  by  a  six-inch  belt. 


254 


THE  MANUFACTURE  OF  LEATHER. 


Fig.  69. 


UNION  WHITENING  AND  BUFFING  MACHINE. 


This  machine  is  almost  indispensable  in  a  leather  finishing 
shop,  in  fact  we  know  of  few  machines  which  are  so  desirable 
and  profitable. 

SHAVING  MACHINE. 

Fig.  70  shows  the  Rood  improved  shaving  machine,  manu- 
factured by  the  Vaughn  Machine  Co.,  Peabody,  Mass. 

This  machine  is  guaranteed  to  be  a  first-class  machine  in 
every  respect  for  shaving  the  alum,  acid  and  combination 
tannages.  These  machines  are  successfully  used  by  the  leading 
manufactures  in  shaving  kip,  calf,  goat  and  sheep,  and  are 
acknowledged  to  do  superior  work  to  any  machine  or  hand- 
work, and  is  used  now  almost  exclusively  for  shaving  by  all 
manufacturers  of  leather. 

The  side  frames  and  braces  are  planed  and  bolted  together. 


WHITENING  AND  SHAVING  LEATHER. 


255 


and  are  supported  by  a  heavy  bed-frame,  thus  making  it  im- 
possible for  the  working  parts  to  wear  unevenly,  by  the  work- 
ing of  the  side-frames,  owing  to  an  unsteady  floor. 


Fig.  70. 


11~  'Hllffl™ 

ROOD  SHAVING  MACHINE. 


The  cutter  is  a  new  departure  from  all  others  now  in  use. 
The  blades  meec  in  the  centre  of  the  cylinder,  and  each  pair 
have  an  extra  cutter  that  cuts  out  the  centre  in  advance  of  each 
other,  thus  allowing  them  to  enter  the  skin  to  the  depth  of  the 
cut  they  are  to  take. 

With  this  improved  cutter  cylinder,  the  Rood  shaver  is  able 
to  shave  the  best  quality  skins  and  give  the  desired  soft  finish. 


CHAPTER  XVIII. 


BLACKING  LEATHER. 


THE  side  of  leather  having  passed  through  the  previously 
described  operations,  and  been  last  boarded  is  now  in  the  state 
for  blacking,  and  this  is  performed  either  by  hand  or  machinery. 
It  is  thought  by  manufacturers  that  the  hand  process  is  pre- 
ferable for  the  heavy  grades  of  upper  leather;  but  upon  what 
ground  it  is  not  plain,  as  some  of  the  machines  constructed  for 
this  purpose  are  models  of  mechanism,  and  perform  the  work 
much  more  economically  and  thoroughly  than  is  usually  done 
by  the  hand  process. 

Figs.  71  and  72  show  the  two  forms  of  blacking  brushes  in 
common  use,  and  they  are  made  both  soft  and  stiff ;  the  best 
quality  are  extra  copper-wired,  and  are  all  bristle.  The 
oval  form  is  always  made  with  a  strap ;  but  the  round  form 
has  either  handles  or  straps.    Both  brushes  are  made  in  first 


and  second  qualities  ;  but  it  is  economy  to  purchase  the  best 
made,  as  the  extra  wear  more  than  compensates  for  the  small 
difference  in  price. 

Brushes  for  blacking  leather  are  made  in  both  the  oval  and 
round  form  by  the  Vaughn  Machine  Co.,  Peabody,  Mass. 


Fig.  71. 


Fig.  72. 


(  256) 


BLACKING  LEATHER. 


257 


batcheldf.r's  leather  blacking,  coloring  and  dressing  machine. 

Figs.  73  to  85  show  the  leather  blacking,  coloring  and  dress- 
ing machine  patented  by  Batchelder,  and  built  by  the  Vaughn 
Machine  Co.,  Peabody,  Mass. 

F'g-  73  >s  a  left-hand-side  elevation  of  a  machine  embodying 
Batchelder's  invention  ;  Fig.  74,  a  front  view  thereof,  with  the 
table  ;/  omitted;  Fig.  75,  a  longitudinal  vertical  section  of  Fig. 
74;  Fig.  76,  an  enlarged  detail  to  be  referred  to;  Fig.  77,  a 
detail  in  top  view  of  Fig.  76,  with  the  brush  c  omitted,  and  Fig. 
78  is  a  modification  to  which  reference  will  be  made. 


Fig.  73. 


 I— I  Li  toL  

This  machine  will  also  black  grain  leathers  and  season  oil 
skins. 

The  blacking  or  liquid  dressing,  or  material  to  be  applied  to 
the  upper  surface  of  the  hide  or  skin,  B,  is  placed  in  the  recep- 
tacle e,  which  is  shown  as  an  open  box,  the  sides  of  which,  at 
its  lower  end,  are  concaved,  to  fit  the  periphery  of  the  recep- 
tacle-roller e',  which  may  be  made  to  travel  near  the  straight 
lower  edge,  2,  of  the  bottom  of  receptacle  by  means  of  the  ad- 
justing screws  e'2,  the  amount  of  space  between  the  edge  of  the 
bottom  of  the  receptacle  c  and  the  roller  e'  determining  the 
17 


BLACKING  LEATHER. 


259 


amount  of  blacking  or  dressing  to  be  delivered  to  the  brush  c. 
The  roller  e'  may  be  driven  more  or  less  rapidly  to  carry  or  de- 
liver more  or  less  blacking  or  dressing  to  the  brush 
c.    This  may  be  done  by  changing  the  size  of  the  ^^-^c 
gear  e3  on  the  journal  of  the  roller  e',  the  toothed 
speed-wheel  f,  which  engages  the  gear  e3  and  drives  <jifl|^ 
the  roller  e',  being  mounted  on  a  stud  of  an  ad- 
justable  carrier,/"',  provided  with  a  locking  device, 
ft,  to  engage  an  arch,  ft,  and  hold  the  carrier  in  proper  position. 

It  is  preferable  to  slightly  groove,  flute,  or  pit  the  roller  e' ,  to 
enable  it  to  take  up  a  greater  quantity  of  blacking  or  dressing. 
The  hide  or  skin  as  it  leaves  the  supporting-surface  a*  is  deliv- 
ered upon  an  endless  belt  or  moving  bed,g,  shown  as  composed 
of  cords  or  tapes  extended  about  rollers  g'  g3,  the  one  g'  being 
driven  positively  from  the  toothed  wheel  b  by  the  intermediate 
worm,  //,  which  engages  the  pinion  h'  at  the  end  of  the  shaft  g1 . 
The  tanned  hide  or  skin  to  be  dressed  is  introduced  between 
the  supporting-surface  «4  and  roller  or  brush  c  under  a  roller,  /, 
which,  as  clearly  shown  in  Figs.  75  and  76,  has  its  journals 
mounted  on  levers  or  arms  pivoted  at  /'  and  acted  upon  by 
springs  /*,  to  keep  the  roller  depressed  upon  the  hide  or  skin  to 
properly  hold  it.  The  front  ends  of  the  levers  or  arms  /'  are 
joined  to  a  holding-bar,  m,  which  is  of  a  shape  to  fit  the  space 
between  the  brush  c,  the  support  a*,  and  roller  /.  The  under 
side  of  this  holding-bar  (see  Fig.  76)  is  so  shaped,  curved,  and 
located  with  relation  to  the  surfaces  of  the  roller  /  and  the  sup- 
porting-surface aA  as  not  to  bear  upon  the  hide  or  skin  until 
after  the  passage  of  the  edges  of  the  same  beyond  the  nip  of  the 
roller  /,  the  holding  bar  being  devised  to  act  upon  and  hold  the 
end  of  the  hide  or  skin,  after  passing  beyond  the  nip  of  roller  / 
(the  latter  then  dropping),  and  prevent  the  hide  or  skin  being 
drawn  in  too  rapidly.  In  front  of  the  apparatus  there  is  placed 
a  table,  n. 

In  some  instances  and  for  some  classes  of  work  the  inventor 
modifies  the  machine  so  far  described,  as  represented  in  Fig. 
78,  and  where  there  is  shown  the  roller  /  as  elevated  consider- 


26o 


THE  MANUFACTURE  OF  LEATHER. 


ably  above  the  position  shown  for  it  in  Figs.  75  and  76,  and 
in  such  position  there  will  be  left  sufficient  space  to  permit  the 
operator  to  retain  hold  of  and  control  the  position  and  move- 
ment of  the  hide  or  skin  being  acted  upon  by  the  brush  or  rol- 
ler c,  and  in  such  case  also  the  holding-bar  ;;/  is  omitted. 

To  prevent  the  blacking  or  dressing  being  thrown  from  the 
brush  or  roller  c  toward  the  front  of  the  machine  there  is  pro- 
vided the  auxiliary  spatter-guard  0.  The  roller  /  and  the  holder 
m,  when  used,  also  serve  to  prevent  the  blacking  or  liquid 
dressing  from  being  thrown  out  at  the  front  of  the  machine. 
The  supporting-surface  a*  and  brush  c  are  as  long  as  the  maxi- 
mum width  of  the  hide  or  skin  to  be  blacked  or  dressed  ;  but  as 
the  hides  or  skins  being  finished  or  dressed  are  always  different, 
both  as  to  width  and  outline  at  their  edges,  it  results  that  the 
brush  c  always  applies  blacking  or  dressing  to  more  or  less  of 
the  surface  a\ 

The  blacking  or  dressing  applied  to  the  surface  a1  must  all 
be  removed  and  the  surface  left  clean  so  as  not  to  apply 
blacking  or  dressing  to  the  under  side  of  the  hide  or  skin  as  it 
comes  in  contact  with  it.  To  do  this  the  inventor  has  provided 
a  wiper  or  cleaner,  p  (shown  clearly  in  Figs.  74  and  75),  as  a 
strip  of  flexible  material  held  by  a  suitable  adjustable  bar,  p', 
so  that  the  edge  of  the  wiper  or  cleaner  may  be  pressed  with 
more  or  less  force  against  the  surface  a*,  the  degree  of  its  pres- 
sure being  preferably  regulated  by  adjusting-screws  p3,  The 
material  wiped  or  scraped  from  the  surface  a*  drops  into  the 
trough  q  and  passes  therefrom  into  a  suitable  pail  or  bucket  to 
be  rinsed,  if  desired. 

By  driving  the  brush-roller  c  and  the  supporting  surface  a* 
independently,  the  inventor  is  enabled  to  rotate  either  at  any 
desired  speed,  and  thus  rub  the  blacking,  coloring,  or  dressing 
matter  more  or  less  into  the  surface  of  the  hide  or  skin. 

The  bearings  for  the  brush  c  and  roller  c'  will  preferably  be 
made  adjustable  vertically  to  accommodate  for  the  thickness  of 
the  leather  and  compensate  for  wear. 

Batchelder  in  1883  patented  an  improvement  on  the  machine 


BLACKING  LEATHER. 


26l 


just  described,  which  improvement  is  shown  in  Figs.  79  to  82. 
In  the  machine  described  in  Figs.  73  to  78,  the  brush-roller 
which  applied  the  blacking  or  the  liquid  dressing  to  the  leather 
on  a  rotating  supporting  surface  or  roll  had  its  bristles  set 
radial ;  but  with  such  a  brush  the  distribution  of  the  blacking 
is  not  so  uniform  and  thorough  as  is  desirable  ;  so  to  cause  the 
brush  to  apply  the  blacking  to  every  minute  part  of  the  face  of 
the  leather  being  blacked  or  treated,  Batchelder  has  inclined 
the  bristles  of  the  alternate  rows  of  bristles  of  the  brush  in  dif- 

Fig.  79.  Fig.  80. 


if 


ferent  directions,  those  of  one  row  inclining  toward  one  end  of 
the  cylinder  and  those  of  the  next  alternate  row  toward  the 
opposite  end  of  the  cylinder,  so  that  the  ends  of  the  bristles, 
besides  traveling  over  the  leather  in  the  direction  of  rotation 
of  the  brush-roller,  also,  when  in  contact  with  the  leather,  spring 
or  yield  in  opposite  directions,  the  free  ends  of  the  bristles  of 
alternate  rows  moving  in  opposite  directions  longitudinally  as 
compared  with  the  axis  of  the  brush-roll,  thus  working  the 
blacking  backward  and  forward  across  the  leather,  as  well  as  in 
the  direction  of  its  movement  over  the  supporting-surface.  In 


262 


THE  MANUFACTURE  OF  LEATHER. 


this  way  every  particle  of  the  upper  side  of  the  leather  is  effec- 
tually blacked  and  streaks  are  effectually  prevented. 

Fig.  79  represents  in  section  a  sufficient  portion  of  a  leather 
blacking  or  dressing  machine  to  illustrate  the  present  improve- 
ment ;  Fig.  80,  an  end  view  of  the  brush-roller  on  a  larger 
scale;  and  Figs.  81  and  82,  two  partial  sections  thereof  in  the 
dotted  lines  x  and  j/. 

The  supporting  bed  a4,  color-roller  e',  deflector  d,  spatter- 
roller  b'  and  roller  i  are  as  in  the  machine  shown  in  Figs.  73  to 
78.  The  roller  c,  which  applies  blacking  to  the  leather  B,  has 
its  alternate  longitudinal  rows  of  bristles  a  b  inclined  in  oppo- 
site directions,  those  of  one  row  being  as  in  Fig.  81,  and  those 
of  the  next  row  as  in  Fig.  82,  so  that  as  the  bristles  yield  on 
coming  in  contact  with  the  leather  B  those  of  one  row,  as  in 
Fig.  81,  will  yield  and  move  toward  the  left  end  of  the  brush- 
eylinder,  while  those  of  the  adjacent  row  (see  Fig.  82),  oppo- 
sitely inclined,  will  move  toward  the  right  of  the  cylinder,  the 
bristles  of  the  two  rows  thus  moving  over  the  leather  one  after 
the  other  in  opposite  directions,  in  the  direction  of  the  length 
of  the  supporting  roller  a4,  at  the  same  time  that  all  the  bristles 
sweep  over  the  leather  as  it  is  carried  under  it  by  the  roller  a4. 
In  this  way  the  blacking  is  brushsd  on  the  leather  both  longi- 
tudinally and  transversely.  The  brush- cylinder  has  a  metal 
journal  at  each  end.  the  journal  preferably  forming  part  of  a 
metal  shaft  extended  through  the  cylinder  c  of  wood.  The  cyl- 
inder c  is  provided  with  a  series  of  diagonal  holes  at  opposite 
inclinations  (see  Figs.  81  and  82),  into  which  the  bristles  a  b 
are  inserted  and  held  by  glue  and  wooden  plugs  or  galvanized 
nails,  or  in  any  usual  manner. 


CHAPTER  XIX. 


MACHINES  FOR  ROLLING,  PEBBLING,  GLASSING  OR  POLISHING, 

FINISHING,  ETC. 

THE  leather  after  being  properly  blacked  is  next  submitted 
to  one  of  the  finishing  processes,  and  while  this  operation  is 
sometimes  performed  by  hand,  still  by  far  the  greater  part  of 
the  leather  curried  in  this  country  is  glassed  by  machinery,  and 
a  large  number  of  contrivances  have  been  invented  for  this  pur- 
pose, as  well  as  for  pebbling,  finishing  and  similar  operations. 
The  scarcity  of  labor  in  all  the  Northern  States  from  the  com- 
mencement of  the  late  war  of  the  rebellion,  and  the  enormous  de- 
mand for  leather  which  immediately  arose,  stimulated  inventors 
in  all  lines  of  leather  production,  and  machinery  for  this  purpose 
which  came  into  use  from  i860  to  1873  is  still  the  kind  that  is 
now  commonly  employed  with  many  improvements  in  all  sec- 
tions of  the  country. 

The  glazing  machine  was  one  of  the  first  steam-driven  tools 
introduced  into  the  trade.  It  was,  at  first,  thought  it  would  do 
away  with  hand-glazing  entirely,  but  subsequent  developments 
proved  that  it  could  only  be  utilized  upon  the  heavier  grades  of 
stock. 

The  present  machine,  however,  is  a  vastly  improved  and 
much  more  delicate  piece  of  mechanism,  to  which  the  finest 
grades  of  stock  can  be  entrusted  without  fear  of  its  being  burnt 
or  torn  into  fragments. 

In  Fig.  83  is  shown  an  illustration  of  the  Bowers  Rocker- 
Motion  Leather  Finishing  Machine,  made  by  Albert  M.  Bowers, 
Newark,  N.  J. 

This  machine  is  now  largely  used  for  glazing,  rolling,  peb- 
bling, stoning,  brushing  and  finishing  leather,  and  it  is  an  im- 

(  263  ) 


264  THE  MANUFACTURE  OF  LEATHER. 

Fig.  83. 


BOWERS  ROCKER-MOTION  LEATHER  FINISHING  MACHINE. 


provement  over  other  modes  of  finishing  leather  in  the  method 
of  construction  over  other  machines. 

The  rocker  motion  insures  economy  of  power,  the  rocker  be- 
ing the  segment  of  the  circle,  while  other  machines  are  made 
with  a  slide  or  pendulum,  or  with  a  link  motion,  and  the 
adaptation  of  the  rocker  as  a  resisting  power  removes  all  fric- 
tion possible.    At  the  same  time  it  insures  the  machine  to  run 


MACHINE  FOR  ROLLING,  PEBBLING,  ETC. 


265 


without  heating  and  without  flinging  oil  upon  the  leather  while 
it  is  in  operation,  two  very  important  factors,  as  a  spot  of  oil 
upon  fancy  leather  would  spoil  the  whole  skin. 

Mr.  Bowers  also  gets  great  power  for  rolling  and  pebbling.  In 
the  construction  of  the  machine,  the  larger  part  is  wood.  The 
wooden  part,  being  the  resisting  part,  is  in  direct  sympathy 
with  the  leather,  and  while  the  machine  could  be  built  of 
iron,  yet  machines  built  of  iron,  Mr.  Bowers  claims,  are  too 
rigid  in  practice  to  work  upon  leather,  having  been  demon- 
strated many  times  upon  the  same  kinds  of  leather.  There- 
fore this  machine  takes  the  lead  of  other  machines  for  like  pur- 
poses, and  is  a  studied  improvement  over  'first  machines 
manufactured. 

With  it,  it  is  also  possible  to  stone  out  hides  preparatory  for 
the  splitting  machine.  All  kinds  of  leather,  the  whole  hide  or 
the  sides,  sheep  skins,  goat  skins,  skivers,  bag  leather,  and  all 
kinds  of  leather  that  are  made  to  imitate  natural  grains,  can  be 
pebbled  with  it.  In  glazing,  it  will  glaze  every  kind  of  leather 
to  the  greatest  success.  It  will  glaze  the  whole  hide,  the  sides, 
sheep  skins,  skivers,  goat  skins  ;  is  used  for  glassing,  shoe  grain, 
polish  leather,  bag  leather,  harness  leather,  brush  backs,  hat 
sweats,  on  cloth  and  paper  imitations  of  leather,  on  the  thinnest 
buffings.  Will  glaze  the  different  shades  of  colored  leather  to 
perfection,  being  free  from  danger  to  fling  oil  upon  colored 
leather.  It  is  used  for  glassing  out  suspender  leather,  insole 
splitts,  buffings,  heavy  belt  leather,  and  in  fact  it  is  used  on 
every  kind  of  leather  that  is  required  to  be  glazed. 

Used  also  for  rolling  shoulders  and  trimmings,  calf-skins  for 
pocketbook  stock  in  all  its  branches,  for  glazing  alligator,  lizard 
and  snake  skins,  and  has  been  subjected  to  the  severest  trials, 
and  most  arbitrary  requirements.  Over  1775  of  these  machines 
are  in  operation  to-day. 

It  is  also  being  extensively  used  in  pocket-book  factories  to 
glaze  the  small  pieces  of  stock  after  having  been  cut  into  the 
different  sizes  and  shapes  for  pocket  books,  after  the  edges  have 
been  shaved  to  restore  the  gloss  to  the  pieces  from  finger-marks 
and  other  handling. 


266 


THE  MANUFACTURE  OF  LEATHER. 


The  improved  iron  glassing  jack,  made  by  J.  T.  Freeman  & 
Co.,  Woburn,  Mass.,  is  shown  in  Fig.  84. 

Fig.  84. 


IMPROVED  IRON  GLASSING  JACK. 


This  is  a  self-contained  machine,  all  of  iron  and  steel  but  the 
table.  It  has  no  posts  or  braces,  and  the  peculiar  construction 
of  the  frame  insures  great  rigidity  and  consequent  effectiveness. 
It  is  so  constructed  that  the  pressure  can  be  regulated  by  a 
small  hand-wheel  in  front  of  the  bed.  There  is  also  a  bolster 
stretcher  attached  to  lower  end  of  the  bed,  to  draw  up  the 
stretch  of  the  bolster.  The  machine  requires  no  special  setting 
up,  as  it  is  shipped  altogether  on  a  wooden  base  ;  all  that  is 
necessary  is  to  level  up  same  and  bolt  firmly  to  the  floor.  The 
manufacturers  guarantee  this  machine  to  work  equally  as  well 
on  the  paste  or  black ;  also  on  buff,  harness  or  belt  leather. 

Fig.  85  shows  the  improved  straight  bed  rolling  or  pebbling 
jack  made  by  J.  T.  Freeman  &  Co.,  Woburn,  Mass. 

Owing  to  the  increased  demand  for  a  straight  bed  pendulum 
machine,  and  being  desirous  of  having  a  jack  of  a  different  con- 
struction from  any  other  manufacturer,  the  builders  designed 
the  above  machine.  The  bed  of  this  jack  is  perfectly  straight; 
the  arrangement  under  the  bed  is  the  same  as  a  pair  of  scales, 
thus  giving  an  equal  pressure  on  all  parts  of  the  stroke,  and  has 


MACHINE  FOR  ROLLING,  PEBBLING,  ETC.  267 

only  one  small  spring  in  the  center.  It  is  a  very  heavy  ma- 
chine and  works  equally  as  well  on  light  or  heavy  stock.  The 
builders  have  given  this  machine  a  thorough  trial  and  feel  safe 
to  say  that  it  is  second  to  none  on  the  market. 

The  anti-friction  roll  made  by  J.  T.  Freeman  &  Co.,  Woburn, 
Mass.,  is  especially  adapted  for  heavy  work,  also  on  colored 
leather  and  skins.    It  requires  no  oil,  and  thus  overcomes  all 


Fig.  85. 


IMPROVED  STRAIGHT  BED  ROLLING  OR  PEBBLING  JACK. 


grease-spots  on  the  leather.  The  makers  will  guarantee  it  not 
to  heat  or  burn  the  leather,  but  to  warm  up  just  enough  to  give 
a  good  bright  polish  on  the  stock.  Rolls  can  be  furnished  to 
fit  almost  any  rolling  or  pebbling  jack. 

martin's  improved  machine. 

Martin's  improved  machine  is  shown  in  Fig.  86. 

It  is  built  by  William  F.  Martin,  Salem,  Mass. 

For  simplicity  of  design,  compactness,  easy  and  silent  action, 
facility  of  adjustment,  quantity  and  quality  of  the  work  it  will 
perform,  and  the  high  rate  of  speed  at  which  it  can  be  operated, 
it  needs  only  to  be  examined  to  commend  itself  to  every  one 


268  THE  MANUFACTURE  OF  LEATHER. 


Fig.  86. 


martin's  improved  machine. 


using  machinery  in  all  the  branches  of  the  leather-finishing  in- 
dustry. 

In  currying  it  will  "set  out"  pebble,  "  stone  out,"  "glass  in 
black  and  paste,"  using  either  oil  or  soap  blacking,  entirely 
without  hand  labor. 

For  the  morocco  or  lining  finisher  it  will  glaze,  roll,  pebble 
and  glass  out,  doing  a  quality  of  work  equal  to  any  machine 
now  in  use. 

THE  KNOX  IMPROVED  INCLINED  BED  LEATHER   FINISHING  AND 
PEBBLING  MACHINE. 

In  Fig.  87  is  shown  an  illustration  of  the  Knox  improved  in- 
clined bed  leather  finishing  and  pebbling  machine,  built  by  the 
David  Knox  &  Sons  Machinery  Company,  Lynn,  Mass.  This 
machine  can  be  used  for  finishing  and  pebbling  all  kinds  of 
leather. 

A  medal  and  diploma  were  awarded  these  machines  at  the 
Centennial  Exhibition  for  "  excellence  of  work  done,  sim- 
plicity and  durability  of  all  parts,  and  for  the  little  power 
needed  to  operate  them,  and  ease  in  adjusting  and  running 
them,  they  stand  beyond  all  question  unrivaled."  The  frames 
have  been  re-designed,  adding  greatly  to  their  strength  and 


MACHINE  FOR  ROLLING,  PEBBLING,  ETC. 


269 


Fic;.  87. 


THE  KNOX  IMPROVED  INCLINED  BED  LEATHER  FINISHING  AND  PEBBLING  MACHINE. 

rigidity.  All  these  machines  are  now  furnished  with  the  new 
slotted  balance-wheel,  having  an  adjustable  stroke  from  16  to 
32  inches,  and  making  a  very  easy  and  smooth-running  motion. 
The  outside  bearings  recently  put  on  give  great  steadiness  and 
smoothness  to  the  motion  of  these  machines. 

Patents  have  been  granted  for  improved  adjustments  for  the 
bed.    Besides  giving  a  range  of  nearly  three  inches  for  raising 


270 


THE  MANUFACTURE  OF  LEATHER. 


the  bed,  the  adjustment  for  regulating  the  tension  of  the  springs 
is  absolutely  separate  from  and  independent  of  that  raising  the 
bed.  This  allows  the  most  perfect  and  delicate  adjustments 
to  be  accomplished  with  ease  and  facility. 

These  machines  are  used  in  polishing,  glazing,  dicing  and 
pebbling  all  grades  of  leather  with  the  same  remarkable  success, 
from  the  lightest  French  kid  to  the  heaviest  currier's  work.  The 
best  evidence  of  the  value  of  these  machines  is  shown  by  the 
increased  sales  during  the  past  five  years,  and  the  large  num- 
ber used  by  the  leading  firms  in  this  country,  many  running 
constantly  from  five  to  fifteen  machines. 

An  extra  wide  bed,  carrying  a  strap  six  inches  wide,  is 
especially  adapted  for  currier's  work. 

The  Company  also  makes  an  improved  level  bed  bottom  fin- 
ishing and  pebbling  machine.    They  claim  for  these  machines  : 

First :  Great  strength  and  rigidity  of  frame — qualities  in  which 
they  excel  all  other  machines  made. 

Second  :  That  these  machines  are  complete  in  themselves — 
not  havfng  any  of  their  working  parts  attached  to  or  depending 
on  the  building,  and  well-balanced  in  all  their  movements,  so 
that  in  running  at  any  speed,  they  will  not  rack  or  injure  the 
building. 

Third  :  A  range  and  ease  in  adjustment  possessed  by  no  other 
machine. 

Fourth:  That  the  adjustments  for  the  bed  are  simplicity 
itself,  and  are  independent  of  each  other.  They  are  all  within 
easy  reach  of  the  operator,  who  has  the  machine  under  com- 
plete control  without  changing  his  position  for  glazing.  The 
whole  bed  can  be  instantly  dropped  one-half  inch,  clear  of  the 
tool,  and  as  quickly  raised  into  position  for  work.  This  allows 
the  machine  to  be  run  all  the  time  without  any  useless  wear  on 
the  strap,  a  very  important  feature,  for  which  the  Company  has 
patents  pending. 

Fifth:  That  there  is  absolutely  no  wear-out  to  any  of  the 
working  parts  of  the  bed,  and  no  possibility  of  its  getting  out  of 
order  by  the  work. 


MACHINE  FOR  ROLLING,  PEBBLING,  ETC. 


271 


Plain  and  figured  agates,  glasses  and  flints,  leather,  wood  and 
fibre  straps,  smooth  and  pebbling  rolls  of  all  kinds  furnished  to 
order. 

Fig.  88  shows  the  celebrated  Coombs  Pendulum  Jack  made 
by  the  Vaughn  Machine  Company,  Peabody,  Mass. 


Fig.  88. 


COOMBS  PENDULUM  JACK. 


What  the  manufacturers  claim  for  it  is : 

First:  That  it  is  all  iron  and  steel  except  the  face  of  the  bed. 
It  is  all  contained  in  one  frame,  and  consequently  cannot  get 
out  of  line,  there  being  no  wood  to  shrink  and  become  loose. 

Second  :  That  we  use  a  straight  bed,  which  gives  the  opera- 
tor better  control  of  the  leather  and  does  not  wear  out  the  bol- 
ster, as  the  curved  bed  does. 

Third:  That  our  jack  will  run  25  per  cent,  easier  than  any 
other  jack  doing  the  same  work. 


272 


THE  MANUFACTURE  OF  LEATHER. 


Fourth  :  That  it  is  heavier,  stronger  and  more  durable,  be- 
ing made  of  the  best  material  and  in  the  most  workman-like 
manner. 

Fifth  :  That  the  arrangement  of  the  bed  is  entirely  new,  and 
is  the  best  that  has  been  produced  by  any  one  so  far.  The 
reason  is  this,  that  you  can  get  an  absolute  even  pressure  all 
over  the  bed  and  more  elasticity  than  on  any  other  machine. 
You  can  also  have  perfect  control  of  the  bed  from  the  front 
of  the  machine,  one  screw  raising  or  lowering  both  ends  of  the 
bed  at  the  same  time,  and  one  screw  regulates  the  pressure  for 
both  ends  of  the  bed.  There  are  also  two  other  screws  to  ad- 
just the  bed  to  any  desired  position. 

Sixth :  That  our  jack  can  be  run  with  less  repairs,  as  all  the 
bearings  are  babbitted,  and  the  boxes  have  caps  to  take  up  the 
lost  motion. 

Seventh  :  That  our  machine  occupies  the  least  possible  space, 
the  height  7  feet  10  inches,  the  floor  space  6  feet  by  7  feet. 

This  machine  is  designed  especially  for  printing,  or  any  heavy 
work.  The  manufacturers  build  this  machine  lighter  to  do 
glassing  and  polishing. 

They  also  make  and  cut  pebbling  rolls  of  any  pattern  desired. 


CHAPTER  XX. 


STAKING  MACHINES. 

THE  "hand-method  "  staking  machines  (shown  in  Fig.  89), 
built  by  F.  F.  Slocomb  &  Co.,  Wilmington,  Del.,  is  now  fitted 
where  required  with  a  swivel  pressure  adjustment  of  novel  de- 
sign, which  is  claimed  to  be  far  more  practical  and  exact  than 
any  prior  device  for  the  purpose.  Other  recent  improvements 
enable  this  machine  to  stake  successfully  many  classes  of  work 


Fig.  89. 


"  HANI)  METHOD  "  STAKING  MACHINE. 


heretofore  either  impossible  to  do  on  any  machine  or  else  in- 
differently done.  Among  these  may  be  mentioned  several 
varieties  of  fine  glove  leather,  fine  kid,  alum,  sheep  and  lambs, 
etc.,  and  chrome  tanned  skins  generally.  On  kangaroo  and 
kangaroo  calf,  etc.,  and  Russia  calf,  the  firm  state  that  their 
improved  combination  padding  and  staking  jaws  of  leather  and 
felt  will  surprise  users  by  the  fine  quality  of  work  done.  In 
addition  they  have  two  other  sets  of  staking  jaws,  all  different 
and  giving  different  results,  thus  fitting  one  machine  to  do 
many  lines  of  work  by  merely  changing  the  jaws.  The  ad- 
vantage of  this  has  been  shown  many  times  over  in  factories 
18  ^273) 


274 


THE  MANUFACTURE  OF  LEATHER. 


where  any  change  in  tanning  or  finish  has  occurred.  Ma- 
chines are  built  in  four  sizes,  suitable  for  any  work,  from  lamb 
skins  to  whole  hides. 

This  machine  takes  the  place  of  knee  or  arm  staking  and  pad- 
ding on  light  work,  and  soft  boarding  on  heavy  work. 

The  staking  machine  is  a  marked  improvement  over  the 
hand  stake.  This  latter  was  not  used  in  the  morocco  branch 
of  the  trade  until  the  dawn  of  the  present  era  of  chrome  tan- 
nage. It  was  an  upright  wooden  stake,  some  two  feet  in 
length  and  eight  inches  in  width,  into  the  tapering  top  of 
which  was  fixed  a  broad  steel  blade.  The  skin  was  drawn 
across  this  blade,  the  weight  of  the  workman's  body  being 
thrown  upon  it.  Great  care  was  exercised  in  order  to  guard 
against  cutting  the  skin  ;  should  this  occur,  the  staker's  bal- 
ance would  be  lost,  and  he  would  be  in  danger  of  being  impaled 
upon  his  stake. 

The  staking  machine  accomplishes  the  work  of  a  half  dozen 
hand  stakers.  There  are  several  makes  in  use,  and  improve- 
ments are  constantly  being  added. 

The  staking  machine  shown  in  Fig.  90  is  built  under  the 
Stakpole  patent  by  the  Vaughn  Machine  Co.,  Peabody,  Mass., 
and  it  successfully  meets  all  the  requirements  of  the  morocco 
and  light  leather  trade.  The  leather  is  staked  with  the  grain 
side  up,  so  the  operator  sees  just  what  is  being  done  through 
the  whole  operation. 

The  tension  is  instantly  applied  or  released  by  hand  or  foot, 
and  the  jaw  with  its  flexible  fibre  pad  cannot  be  equaled  by 
any  other  device  for  this  work. 

It  will  take  out  the  stretch  in  the  leather  thoroughly,  softens 
perfectly  and  no  damage  or  tearing.  No  danger  of  grease 
spots  or  soiling  in  the  least  any  fancy  colored  stock. 

Floor  space  required,  only  4^  ft.  x  3  ft.  Simplicity  of  con- 
struction and  operation.  Self-contained  and  no  jar  or  noise 
perceptible  when  it  is  in  operation.  Minimum  of  power  re- 
quired, a  two-inch  belt  will  run  it.  Maximum  amount  of  work 
obtained. 


STAKPOLF.  STAKING  MACHINE. 

Fig.  91  shows  the  staking  machine  built  by  Wm.  F.  Martin, 
Salem,  Mass.  It  can  be  adjusted  to  any  kind  of  leather,  in- 
cluding napa.    For  napa  an  extra  tool  is  required  for  spread- 


Fig.  91. 


martin's  staking  machine. 


276 


THE  MANUFACTURE  OF  LEATHER. 


ing  out  the  leather,  and  it  is  furnished  by  the  manufacturer 
when  required.  This  machine  is  unexcelled  on  calf,  kangaroo, 
chrome,  Russia  calf  and  glove  leathers.  It  is  noiseless  in 
action  and  is  run  by  a  smaller  amount  of  power  than  any  other 
staker  on  the  market.  Pressure  can  be  adjusted  while  the 
machine  is  in  operation. 

Staking  machines  are  also  built  by  Geo.  W.  Baker  &  Co., 
Wilmington,  Del.,  and  others. 


CHAPTER  XXI. 


MACHINES  FOR  MEASURING  LEATHER. 

THE  heavy  leathers  are  sold  by  weight;  but  light  leathers, 
such  as  upper,  morocco,  sheep-skin,  and  enamel  leather,  are 
sold  by  area  in  the  United  States.  The  yardstick,  and  the 
common  measuring  frame,  having  wires  or  cords  running  the 
length  and  across  it,  thus  dividing  the  frame  into  square  feet, 
do  not  require  special  description. 

Tanners  of  sole  leather  by  a  quick  process  are  talking  of 
selling  sole  by  measure  instead  of  weight.  They  claim  that  the 
buyer  gets  nothing  but  leather  when  made  by  this  process.  An 
idea  being  broached  by  shoe  manufacturers  is  to  have  the  frac- 
tion of  a  foot  reduced  to  eighths  instead  of  quarters,  as  is  done 
on  the  measuring  machines.  Nearly  all  large  manufacturers 
remeasure  their  leather,  and  discrepancies  are  often  found  be- 
tween theirs  and  the  original  measurement. 

sawyer's  leather  measuring  machine. 

The  Sawyer  self-adjusting  leather-measuring  machine  is 
shown  in  Fig.  92.  It  is  sold  by  the  Sawyer  Leather  Machinery 
Co.,  Boston,  Mass.  It  is  constructed  on  a  different  principle 
from  other  machines  for  measuring  the  areas  of  surfaces,  and 
it  can  be  operated  by  either  hand  or  power. 

A  minimum  of  power  will  run  this  machine,  and  it  can  be 
operated  at  a  fast  or  slow  rate  of  speed  ;  65  revolutions  per 
minute  is  a  good  average,  which  gives  five  sides  in  that  time. 
Wax,  grain,  enamel,  goat  and  sheep-skins  are  perfectly  meas- 
ured by  this  machine,  which  is  made  in  three  different  sizes  (5, 
6  and  10  feet),  to  suit  the  various  leathers.  The  machine  is 
made  of  metal,  and  any  of  the  series  of  wheels  may  be  removed 
or  replaced  without  interfering  with  the  others. 

(  277  ) 


278 


THE  MANUFACTURE  OF  LEATHER. 


Sawyer's  invention  consists  in  an  arrangement  of  levers  by 
which  the  travel  of  each  measuring-wheel  is  caused  to  properly 
affect  the  index  of  the  registering  device. 

The  article  to  be  measured  is  fed  into  the  machine  between 
the  wheels  and  roller,  and  the  leather  is  smoothed  out  as  it 
passes  between  them,  and  so  records  every  inch  in  the  surface. 


Fig.  92. 


sawyer's  leather-measuring  machine. 


Fig.  92  illustrates  a  perspective  view  of  the  front  of  the 
Sawyer  machine. 

For  the  purpose  of  establishing  a  standard  of  measurement 
of  leather,  the  trade  generally  signed  an  agreement  making  the 
Sawyer  measuring  machine  the  standard.    This  is  the  first  and 


MACHINES  FOR  MEASURING  LEATHER. 


279 


only  formal  endorsement  by  the  trade  of  any  invention  whatso- 
ever as  the  standard  of  measure  for  leather. 

The  Sawyer  leather  measuring  machine  was  given  the  high- 
est award,  a  gold  medal,  at  the  great  exhibition  of  the  Massa- 
chusetts Charitable  Mechanics'  Association  in  1884.  Again  at 
the  Exhibition  of  1887,  it  was  in  competition  with  all  of  the 
machines  known  for  the  measuring  of  leather,  and  again  it  re- 
ceived an  award  of  first  class — a  special  diploma,  affirming  the 
award  of  the  gold  medal  for  its  continued  excellence,  while  no 
other  measuring  machine  received  an  award  above  the  fourth 
class.  (For  confirmation  of  this  statement  we  refer  to  the 
records  of  the  Mass.  C.  M.  Association.)  The  reasons  for  this 
distinction  are  that  the  Sawyer  is  the  only  machine  measuring 
accurately  every  description  of  leather  in  any  condition  whatso- 
ever, wrinkled  or  smooth,  and  is  consequently  the  only  machine 
available  to  manufacturers  of  boots  and  shoes  whose  stock 
comes  to  them  folded  and  creased.  It  stands,  therefore,  alone 
in  its  universal  application,  and  is  now  practically  regarded  as 
the  standard  of  measure  for  all  upper  leather  in  the  United 
States,  England  and  Germany. 

THE  UNION  LEATHER  MEASURING  MACHINE. 

F'g-  93  illustrates  the  Union  leather  measuring  machine, 
which  is  offered  to  all  who  deal  in  leather  in  any  form  and  now 
in  constant  and  most  satisfactory  use  by  well-known  dealers. 

Experience  has  demonstrated  that  this  machine  has  no  equal 
for  accuracy,  rapidity,  ease,  and  simplicity  of  action,  and  for 
low  cost  both  of  running  and  of  original  purchase. 

The  machine  is  made  in  three  sizes:  No.  1,  5  x  4;  No.  2, 
6  x  41^  ;  No.  3,  10  x  4^  feet.  The  Union  Leather  Measuring 
Machine  Co.,  Danversport,  Mass.,  who  manufacture  the  ma- 
chine, are  willing  at  any  time  to  meet  all  competitors  in  a  trial 
for  accurate  measurement.  VVm.  O.  Hood,  Danversport,  Mass., 
is  the  agent  for  the  sale  of  the  machine. 

This  machine  is  a  simple  mechanical  arrangement  for  rapidly 
measuring,  within  a  very  small  limit  of  error,  the  superficial 


28o 


THE  MANUFACTURE  OF  LEATHER. 


Fig.  93. 


area  of  any  plain  surface  having  a  close  texture,  regardless  of  its 
irregularity  of  outline.  This  difficult  problem  is  accomplished 
by  means  of  a  flat  grid  or  table  of  suitable  height  and  properly 
framed,  the  area  of  top  being  formed  of  wooden  strips  about 
seven-eighths  of  an  inch  thick  and  set  at  right  angles  to  the 
front,  with  interstices  of  I  yi  inches.  Upon  the  table  the  object 
to  be  measured  is  placed.  Above  the  table,  and  corresponding 
thereto  in  its  area,  is  a  double  frame  hung  upon  anti-friction 
pivots  at  the  back,  so  as  to  open  like  a  trunk  cover,  or  close 
down  to  a  suitably  fixed  distance  from  the  table.  Throughout 
the  entire  surface  of  this  upper  frame  are  suspended,  at  inter- 
vals of  1  ]/2  inches  by  2  inches,  small  wires  (free  to  slide  up 
through  holes)  of  such  sizes  and  lengths  that  each  will  exercise 
the  same  influence  as  to  weight  as  any  other,  that  is  to  say,  the 
nearer  the  fulcrum  the  heavier  the  wire.  The  weight  of  forty- 
eight  of  these  wires  corresponds  to  one  square  foot  of  area,  and 
thus  the  upper  frame  containing  them  being  brought  down  to 
the  table,  the  object  thereon  throws  up  all  the  wires  which  come 
in  contact  with  it,  and  the  ends  of  the  remaining  wires  drop  be- 


MACHINES  FOR  MEASURING  LEATHER.  28 1 

tween  the  slats  of  the  table.  The  released  weight  of  the  wires 
which  have  been  thrown  up  is  indicated  by  a  spring  balance 
down  to  one-eighth  of  a  square  foot.  However  irregular  the 
the  outline,  the  area  will  be  embraced  by  the  pins  down  to  a 
section  of  i  ^  by  2  inches,  the  error  of  one  pin  being  but  the 
forty-eighth  of  a  square  foot;  it  thus  approaches  absolute  accu- 
racy very  closely 

THE  BOLTON  MACHINE. 

J.  P.  Bolton,  Boston,  Mass.,  has  invented  a  planimeter  for 
showing  the  area  of  leather.  The  leather  is  drawn  over  the 
table  between  a  roll  and  a  series  of  integrating  wheels,  mounted 
in  pivoted  and  adjustable  frames.  Back  motion  is  prevented 
by  pawls,  which  can  be  simultaneously  thrown  out  of  action  by 
an  eccentric  operated  by  a  crank  and  handle  bar  when  it  is  de- 
sired to  zeroize  the  apparatus.  The  wheels  have  coiled  in  their 
hubs  cords  leading  to  weights  in  a  series  of  tubes  partially  filled 
with  liquid  and  connected  to  a  tank.  A  tube  is  also  connected 
to  the  tank  and  provided  with  a  float  carrying  a  graduated 
scale.  Whenever  any  wheel  is  rotated  by  a  portion  of  the  skin 
passing  beneath  it,  the  corresponding  weight  is  drawn  up- 
wards. The  movement  of  all  the  weights  is  instigated  by  the 
movement  of  the  water  level  in  the  tube,  and  the  area  is  read 
oft"  from  the  scale. 


CHAPTER  XXII. 


MINERAL    TANNING    SUBSTANCES — "CHROME,"    OR  MINERAL 
TANNAGE — CHARACTERISTICS  OF  CHROME-TANNED 
LEATHER — CURRYING — DYEING. 

THE  use  of  mineral  tanning  materials  dates  back  to  very  re- 
mote times,  since  history  teaches  us  that  the  Saracens  used 
alum  and  aluminium  salts  for  tanning  skins.  These  substances 
were  in  fact  for  a  long  time  the  only  tanning  materials  em- 
ployed for  preparing  leather,  a  series  of  other  mineral  sub- 
stances for  tanning  having  been  only  recently  introduced  as  a 
substitute  for  vegetable  substances. 

The  principal  mineral  substances  we  have  to  consider  are : 

1.  Alum,  aluminium  sulphate  and  aluminium  acetate. 

2.  Chromates  and  chromic  oxides. 

3.  Hyposulphite  of  soda. 

4.  Ferric  salts. 

5.  Common  salt. 

ALUMINIUM  SULPHATE. 

Neutral  aluminium  sulphate  (Al^SO/)  is  prepared  either  by 
treating  clay  or  bauxite  with  concentrated  sulphuric  acid,  or 
from  cryolite.  In  an  anhydrous  state  it  contains  30  per  cent, 
of  alumina  and  70  per  cent,  of  sulphuric  acid.  With  eighteen 
equivalents  of  water  it  crystallizes  into  octahedrons  or  at  a 
temperature  of  320  F.  into  hexagonal  rhombohedrons.  Alu- 
minium sulphate  is  soluble  in  double  its  weight  of  water.  A 
solution  prepared  with  the  assistance  of  heat  separates,  on 
cooling,  crystalline  lamina  or  aluminium  sulphate  (A123S04  + 
i8H;0).  It  is  found  in  commerce  in  a  nearly  pure  state,  the 
best  qualities  containing  only  traces  of  iron,  but  from  0.5  to  2 
per  cent,  of  free  sulphuric  acid,  which  is  frequently  injurious 

(  282  ) 


"  CHROME,"  OR  MINERAL  TANNAGE. 


283 


when  the  salt  is  to  be  used  for  tanning  purposes.  The  presence 
of  free  sulphuric  acid  may  be  detected  by  adding  to  a  so- 
lution of  aluminium  sulphate  some  logwood  tincture.  The 
solution,  if  free  acid  is  present,  will  be  colored  brown-yellow; 
deep  violet,  if  it  is  neutral.  To  make  aluminium  sulphate  con- 
taining free  sulphuric  acid  available  for  tanning  purposes,  add 
to  a  solution  of  it  1  to  2  per  cent,  of  zinc  chips,  the  solution  of 
which  will  be  attended  by  a  violent  development  of  hydrogen. 
By  the  free  sulphuric  acid  combining  with  the  zinc,  zinc  sul- 
phate is  formed.  An  excess  of  zinc  is  dissolved  with  formation 
of  zinc  sulphate  and  separation  of  basic  sulphate  of  alumina. 
Instead  of  zinc  chips  1  to  2  per  cent,  of  sodium  carbonate  may 
be  used. 

Aluminium  sulphate,  known  in  commerce  as  concentrated 
alum,  is  used  in  tanning  as  a  substitute  for  alum.  The  skin 
absorbs,  according  to  Knapp,  up  to  27  per  cent,  of  it,  which  is 
removed  by  washing  with  water. 

Alum  (A1,3S04+  K.2S04  -  24.H,0),  is  formed  by  the  combi- 
nation of  aluminium  sulphate  with  alkaline  sulphates.  It  is 
readily  prepared  by  mixing  solutions  of  the  two  sulphates.  In 
evaporating  the  fluid,  the  alum  crystallizes  ont.  Potash-alum 
and  ammonia-alum  dissolve  with  difficulty,  they  requiring  18.4 
parts  of  cold  water  and  7.5  parts  of  boiling  water,  while  soda- 
alum  dissolves  readily.  From  a  hot  saturated  solution,  the 
alum  separates  in  octahedrons,  and  from  alkaline  solutions  in 
hexadrons.  The  last  variety  is  called  in  commerce  cubic  alum, 
and,  being  nearly  free  from  iron,  is  valued  more  highly  than 
the  former.  Alum  has  at  first  a  sweetish  taste  which  changes 
into  an  astringent.  By  heating  it  loses  gradually  its  water  of 
crystallization,  becomes  anhydrous,  and  is  converted  into  the 
so-called  burned  alum.  Ferric  sulphate,  manganous  sulphate, 
and  chromium  sulphate,  which  are  isomorphous  with  alumin- 
ium, form  also  double  salts  when  combined  with  potassium, 
sodium,  or  ammonium  sulphate.  The  resulting  combinations 
are  called  iron  alum,  chromium  alum,  and  manganese  alum. 
Instead  of  alumina  they  contain  ferric  oxide,  chromic  oxide  or 


284 


THE  MANUFACTURE  OF  LEATHER. 


manganic  oxide.  They  crystallize  in  the  same  form,  and  con- 
tain an  equal  quantity  of  water  of  crystallization  :  — 

Iron  alum  =  Fe23S04  +  K,S04  +  24H20. 

Manganese  alum  =  Mn.^SO,  +  K.2S04  +  24H20. 

Chromium  alum  =  Cr23S04  +  K2S04  f  24H20. 

If  several  of  these  alums  in  solution  are  present  in  one  fluid, 
the  crystals  separating  from  it  contain  the  different  bases  in 
varying  quantity.  It  is  due  to  this  circumstance  that  alumina 
alum  contains  frequently  iron  alum,  which  it  is  often  impossible 
to  remove  even  by  repeated  recrystallization.  In  tawing  and 
in  mineral  tanning  potash-alum  is  principally  used. 

For  a  complete  saturation  the  skin  tissue  absorbs,  according 
to  Knapp,  7  to  8  per  cent,  of  alum. 

The  tanning  properties  of  alum  are  principally  due  to  the 
alumina  salts  it  contains. 

In  absorption  by  the  skin  tissue,  the  alum,  according  to 
Knapp  and  Raimer,  is  split,  the  aluminium  sulphate  or  basic 
aluminium  sulphate  precipitating  upon  the  fibre,  while  the 
potassium  sulphate  remains  in  the  liquid.  In  the  presence  of 
common  salt  in  aqueous  solution,  the  alum,  according  to  Knapp, 
is  not  converted  into  aluminium  chloride  and  sodium  sulphate. 

Iron  and  chromium  alum  act  upon  the  skin  tissue  in  the  same 
manner  as  aluminium  alum. 

Aluminium  acetate  ( Al26(OC2KsO) )  is  prepared  by  dissolv- 
ing alumina  in  acetic  acid  or  compounding  lead  acetate  with 
aluminium  sulphate  or  alum.  Heating  during  the  process 
should  be  avoided.  Experiments  have  lately  been  made  in 
using  aluminium  acetate  in  place  of  aluminium  sulphate  or  alum. 

It  does  not  separate,  it  is  claimed,  in  a  crystalline  form  in  the 
skin,  and  the  leather  tanned  with  it  does  not  become  spotted, 
as  is  frequently  the  case  in  tanning  with  alum.  The  tanning 
with  this  salt  is  more  solid  than  with  alum,  since  the  aluminium 
acetate  decomposes  more  or  less  in  the  leather  by  the  formation 
of  basic  salts  or  free  alumina. 

A  further  advantage  claimed  for  aluminium  acetate  is  the 
absence  of  free  sulphuric   acid,  which  is  split  off  from  the 


"  CHROME,"  OR  MINERAL  TANNAGE. 


285 


aluminium  sulphate  and  exerts  a  very  injurious  influence  upon 
the  leather. 

CHROMIUM  SALTS. 

Experiments  have  been  made  to  use  chromates  mixed  with 
alumina  salts  for  tanning  in  place  of  vegetable  substances. 

The  most  important  for  this  method  of  tanning  is  potas- 
sium bichromate,  from  which  all  other  chromic  salts  and  com- 
pounds of  chromium  used  for  technical  purposes  are  derived. 
The  salt  is  chiefly  manufactured  in  three  large  eslablishments 
in  England,  from  whence  it  is  sent  to  all  parts  of  Europe  and 
partly  to  America.  It  is  made  by  roasting  a  mixture  of  finely 
powdered  chrome  iron-stone  with  potassium  carbonate  upon  the 
hearth  of  a  reverberatory  furnace  for  several  hours  with  con- 
stant stirring  of  the  mass.  The  chromium  oxide  is  oxidized  to 
chromic  acid,  the  latter  combining  with  the  potassium  to  potas- 
sium chromate.  The  ferric  oxide  contained  in  the  chrome  iron- 
stone is  separated  as  such.  After  thorough  oxidation  the 
roasted  mass  is  lixiviated  with  water,  whereby  potassium  chro- 
mate, a  small  excess  of  potassium  carbonate  and  a  few  impurities, 
such  as  potassium  silicate,  pass  into  solution.  The  liquid 
is  allowed  to  clarify  by  standing,  and,  after  decanting,  is  evapo- 
rated if  necessary,  and  the  neutral  potassium  chromate  con- 
verted into  potassium  bichromate  by  adding  the  required 
quantity  of  sulphuric  acid.  The  potassium  bichromate  forms 
large  bright  garnet-red  triclinic  crystals.  It  is  soluble  with 
difficulty  in  cold  water. 

20      parts  of  water  at   32°  F,  dissolve  I  part  of  salt. 

1 1.8  "  "  "  50  "  "  I  "  " 
7.65  "  •'  "  68  "  "  1  "  " 
1. 18    "       "       "    140    "       "      1       "  " 

Potassium  bichromate  is  very  sensitive.  With  glue,  gelatine, 
gum,  etc.,  it  forms  combinations  which,  after  exposure  to  light, 
are  insoluble  in  water,  its  employment  in  photography  for 
preparing  pigment  or  carbon  pictures  depending  upon  this 
property.  Advantage  is  taken  of  this  fact  in  several  patents 
for  chrome  tannage. 


286 


THE  MANUFACTURE  OF  LEATHER. 


It  precipitates  itself  upon  the  skin  fibre,  and  partially  pene- 
trates it. 

Taken  internally  it  has  a  poisonous  effect  like  most  metallic 
combinations.  Placed  repeatedly  upon  excoriated  or  sore  places 
it  produces  running  ulcers,  which  are,  however,  soon  healed  by 
washing  with  lead  vinegar.  It  colors  the  sound  cuticle  yellow 
without  destroying  it.  In  pulverizing  potassium  chromate  care 
must  be  had  not  to  allow  the  powder  to  enter  the  nostrils,  as  it 
produces  violent  itching  and  severe  spells  of  sneezing. 

Sodium  bichromate  is  more  soluble  in  cold  water  than  potas- 
sium bichromate,  but  it  crystallizes  with  difficulty.  It  is  used 
in  the  two  bath  chrome  processes  ;  but  potassium  bichromate 
is  more  generally  employed. 

Calcium  bichromate,  strontium,  and  barium  are  soluble  in 
water,  while  the  neutral  chromates  of  calcium,  strontium,  and 
barium  are  soluble  with  difficulty,  the  barium  salt,  which  forms 
a  well-known  art  color,  being  almost  insoluble  in  water.  Lead 
salts  give  with  chromic  salts  insoluble  precipitates,  which  are 
used  as  painter's  colors. 

The  neutral  chromates  are  yellow,  readily  soluble  in  water, 
and  can  be  used  in  place  of  the  bichromates,  but  being  dearer 
than  the  latter  offer  no  advantage. 

Chromium  alum  is  the  most  important  of  the  chromium  salts 
thus  far  introduced  in  tanning.  It  is  prepared  by  mixing  chro- 
mium sulphate  with  alkaline  sulphates.  It  crystallizes  from  the 
fluid  in  octahedrons. 

In  speaking  of  alum,  it  has  been  mentioned  that  chromium 
alum  acts  upon  the  fibre  in  the  same  manner  as  aluminium 
alum,  but  the  tanning  of  leather  prepared  with  aluminium  alum 
being,  as  we  will  see  later  on,  more  perishable  on  exposure  to 
water  than  that  of  leather  prepared  with  chromates,  the  latter 
are  preferred. 

Chromic  sulphate  (Cr23S04)  is  obtained  by  reducing  chromic 
acid  to  chromic  oxide,  and  dissolving  in  sulphuric  acid.  It  is 
soluble  in  water,  giving  to  the  latter  an  emerald-green  color, 
and  has  the  same  tanning  effect  upon  the  skin  fibre  as  alu- 
minium sulphate. 


'CHROME,"  OR  MINERAL  TANNAGE. 


287 


HYPOSULPHITE  OF  SODA. 

Hyposulphite  of  soda  is  one  of  the  materials  called  for  by  the 
two  bath  chrome  tannage  processes.  This  article  is  prepared 
as  a  by-product  in  several  of  the  large  European  chemical 
factories.  Attempts  have  been  made  to  make  it  in  this  coun- 
try, but  unsuccessfully  heretofore,  inasmuch  as  it  has  been 
attempted  as  a  main  product,  whereas  the  foreign  manufac- 
turers enjoy  the  advantage  of  its  being  a  by-product.  Of  late, 
however,  there  has  been  successfully  produced  an  American 
product  which  is  proving  to  be  merchantable.  The  increasing 
demand  for  a  purer  and  dryer  hyposulphite  of  soda  has  induced 
a  company  to  start  a  large  plant  for  producing  the  same.  A 
very  fine  quality  of  this  salt  has  been  made  in  this  country  for 
the  past  four  or  five  years,  in  a  limited  way.  The  same  chem- 
ist that  had  charge  of  the  smaller  plant  will  be  in  charge  of  the 
larger  one,  and  it  is  claimed  that  they  can  now  furnish  it  in  any 
desired  quantity  and  of  guaranteed  quality.  The  advantages  of 
the  American  hyposulphite  of  soda  are  that  it  contains  less 
moisture  and  tests  higher  than  the  imported.  A  careful 
analysis  of  several  different  lots  of  German  and  English  show 
that  the  American  contains  from  8  to  10  per  cent,  more  pure 
hyposulphite  than  the  German,  and  from  11  to  15  percent, 
more  than  the  English  make. 

The  muriatic  acid  and  sulphuric  acid  employed  in  the  two 
bath  processes  are  so  well  known  that  no  especial  description 
is  necessary  here. 

FEKRIC  SALTS. 

Tanning  with  ferric  salts  was  already  recommended  in  the 
last  century  by  D'Arcet.  Bordier,  in  1842,  obtained  a  patent 
for  tanning  by  means  of  ferric  sulphate  produced  by  oxidizing 
ferrous  sulphate. 

In  modern  times  Knapp  has  attempted  to  reintroduce  in 
practice  the  method  of  tanning  with  ferric  salts.  The  ferric 
sulphate  used  by  him  is  also  prepared  by  oxidizing  ferrous  sul- 
phate with  nitric  acid,  the  latter  being  added  to  a  solution  of 


288 


THE  MANUFACTURE  OF  LEATHER. 


the  former  until  effervescence  ceases,  and  all  the  ferrous  oxide 
is  converted  into  ferric  oxide.  After  the  cessation  of  the  first 
effervescence  ferrous  sulphate  is  again  added  until  effervescence 
ceases,  the  object  of  this  addition  being  to  reduce  any  excess  of 
nitric  acid  used.  The  resulting  basic  ferric  sulphate  solution 
should  be  of  a  syrupy  consistency,  and  contain  chiefly  basic 
ferric  sulphate  and  a  small  excess  of  ferrous  sulphate. 

Prof.  Knapp  says  that  only  basic  ferric  sulphate  prepared  in 
the  above  manner  is  adapted  for  tanning,  on  account  of  its 
amorphous  condition  and  beautiful  brown-yellow  color  and  the 
indecomposableness  of  its  aqueous  solution  in  boiling,  The 
commercial  basic  ferric  sulphate,  according  to  Knapp,  does  not 
give  a  syrupy  solution,  is  of  a  much  darker  color,  and  the  aque- 
ous solution  is  decomposed  by  boiling. 

This  ferric  salt  is,  according  to  Knapp,  abundantly  absorbed 
by  the  skin  tissue  and  effects  a  complete  tanning  of  the  skin 
fibre.  It  is  claimed  that  the  salt  absorbed  by  the  skin  cannot 
be  removed  by  treating  with  water. 

By  precipitating  a  soap  solution  with  the  above  basic  ferric 
sulphate,  Prof.  Knapp  prepares  an  iron  soap,  which  is  a  combi- 
nation of  ferric  oxide  with  sebacic  acids.  This,  to  complete  the 
tanning  process,  is  mechanically  fulled  into  the  skin,  either  by 
itself  or  mixed  with  fat  solutions  or  emulsions. 

COMMON  SALT 

occupies  an  important  place  in  tanning.  It  serves,  as  has  been 
previously  mentioned,  on  the  one  hand  for  preserving  skins, 
and  on  the  other  to  accelerate  the  tanning  process  in  tawing 
and  mineral  tanning.  As  regards  its  occurrence,  preparation, 
etc.,  nothing  need  be  said. 

The  salt  found  in  commerce  is  either  rock  salt  or  that  ob- 
tained from  salt  springs  or  sea-water,  the  latter  being  known  as 
common  salt.  Both  varieties  contain  varying  quantities  of  ad- 
mixtures, the  principal  being  the  sulphates  of  magnesia,  lime, 
or  gypsum,  and  the  chlorides  of  calcium  and  magnesium. 
Common  salt  prepared  from  sea-water  contains  the  most  im- 


"  CHROME,"  OR  MINERAL  TANNAGE. 


289 


purities,  the  principal  being  magnesium  chloride,  magnesium 
sulphate,  calcium  chloride,  etc.  The  salt  obtained  from  rock 
salt  by  recrystallization  being  the  purest,  is  especially  adapted 
for  use  in  tanning. 

In  using  common  salt  in  tawing  and  mineral  tanning,  admix- 
tures of  magnesium  chloride  and  calcium  chloride  are  espec- 
ially injurious,  as  they  absorb  water  from  the  air,  i.  e.,  they  are 
hygroscopic. 

When  salt  containing  these  admixtures  is  used  for  tanning, 
the  leather  produced  with  it  absorbs  water  from  the  air  and 
becomes  moist. 

"chrome"  or  mineral  tannage. 

Investigators  in  the  field  of  chemistry  and  experimenters  in 
the  art  of  leather  manufacture  have  sought  for  a  long  time  for 
some  mineral  substance  that  could  take  the  place  of  tannin  in 
converting  hides  and  skins  into  leather.  It  may  be  said  that 
Cavalin,  Knapp,  Pfanhauser  and  Heinzerling  were  among  those 
whose  valuable  investigations  opened  the  way  for  future  success. 

The  first  use  of  bichromates  for  tanning  was  made  by  Cavalin. 
The  skins,  according  to  his  method,  are  placed  in  a  solution  of 
22  pounds  of  potassium  bichromate  and  44  pounds  of  alum  in 
396  pounds  of  water,  where  they  remain  for  four  or  five  days 
with  frequent  stirring,  when  they  are  placed  in  a  solution  of  2.2 
pounds  of  ferrous  sulphate  in  22  pounds  of  water.  In  this  they 
remain  for  twelve  hours,  being  in  the  meanwhile  frequently 
stirred.  The  potassium  bichromate  is  reduced  to  chromic  oxide 
by  the  ferrous  sulphate,  and  the  ferrous  oxide  contained  in  the 
ferrous  sulphate  oxidized  to  ferric  oxide,  both  oxides  being 
precipitated  as  such  upon  the  fibre,  or  the  ferric  oxide  together 
with  alumina.  The  fixing  of  the  chromium  combination  is 
effected  by  reducing  the  soluble  chromate  to  chromic  oxide. 
Cavalin's  method  may  be  considered  as  a  combination  of  tan- 
ning with  ferric  aluminium  and  chromic  oxides.  But  a  practical 
application  of  the  process  is  not  possible,  since  the  leather  loses 
its  tannin  easily  when  immersed  in  water,  and  its  grain  is  brittle. 
19 


2go 


THE  MANUFACTURE  OF  LEATHER. 


Knapp,  in  1861,  obtained  a  patent  in  Germany  for  tanning 
with  ferric  salts  and  other  metallic  oxides.  Hides  tanned  with 
mineral  substances  lost,  like  those  tanned  with  alum,  their  tannin 
by  immersion  in  water.  Knapp  tried  to  remove  this  evil  by 
converting  the  metallic  salts  adhering  externally  to  the  skin  into 
insoluble  metallic  soaps,  by  soaking  and  kneading  the  skin  in  a 
soap  solution.  In  order  to  fix  the  tanning  substance  in  the  skin, 
Knapp  recommended,  instead  of  immersing  the  tanned  skins  in 
soap  solution,  the  fulling  in  of  insoluble  soaps  of  ferric  oxide, 
aluminium  oxide,  or  chromium  oxide.  The  solution  of  basic 
ferric  sulphate  Knapp  used  for  tanning  was  prepared  by  com- 
pounding the  solution  with  caustic  soda  until  the  resulting  pre- 
cipitate was  again  dissolved  in  the  fluid. 

Next  to  Knapp,  Pfanhauser  obtained  in  1864  a  patent  for  the 
preparation  of  a  basic  ferric  sulphate  and  its  use  for  tanning. 
By  his  process  ferric  sulphate  is  heated  to  a  red  heat  with  con- 
stant stirring  until  the  mass  is  converted  into  a  reddish  powder. 
The  latter  while  hot  is  thrown  into  water,  in  which,  with  con- 
stant stirring,  it  is  almost  entirely  dissolved.  The  resulting  fluid 
is  allowed  to  clarify  by  standing,  and  the  clear  liquor  used  for 
preparing  tanning  fluid  of  varying  strength.  The  skins  are  first 
placed  in  a  dilute  solution  of  0.50  Beaume,  and  then  succes- 
sively in  stronger  solution.  When  thoroughly  permeated  they 
are  washed  off  and  placed  in  a  soap  solution. 

Knapp,  in  1877,  gave  a  fresh  impetus  to  mineral  tanning  by 
patenting  in  Germany  and  other  countries  a  new  method  of 
tanning  with  ferric  salts,  a  short  description  of  which  process  is 
here  given  : 

In  the  use  of  the  basic  sulphate  of  iron  as  a  tanning  material, 
the  hides  or  skins,  having  the  hair  and  adherent  fleshy  portions 
removed  in  the  usual  manner,  are  placed  in  the  cold  solution  of 
the  ferric  oxide  salt  of  the  proper  density,  in  which  they  are 
allowed  to  remain  for  two,  or,  at  most,  four  days,  during  which 
time  it  is  not  necessary  to  handle  the  hides  in  any  manner,  all 
the  laborious  operations  attending  the  use  of  tan-bark  liquor, 
while  the  hides  or  skins  are  subjected  to  the  action  of  s*ich 


"  CHROME,"  OR  MINERAL  TANNAGE. 


291 


liquor,  being  obviated.  At  the  end  of  the  time  named  the  hides 
or  skins  are  removed  from  the  solution  of  ferric-oxide  salt. 
This  salt  is  prepared  as  follows  :  To  a  boiling  solution  of  sul- 
phate of  protoxide  of  iron  (green  vitriol)  is  added  as  much  nitric 
acid  as  will  thoroughly  oxidize  the  salt  contained  in  said  solu- 
tion. When  the  effervesence  which  ensues  upon  the  addition 
of  the  nitric  acid  has  subsided,  the  operation  is  reversed — that 
is,  sulphate  of  protoxide  of  iron  is  added  to  the  solution  till  said 
solution  assumes  a  syrupy  consistence — a  distinguishing  char- 
acteristic aforementioned — and  acquires  1  yellow-red  color,  also 
characteristic  of  solutions  of  this  iron  oxysalt,  which,  when 
slowly  evaporated  to  dryness,  has  the  appearance  of  an  orange- 
red  transparent  varnish,  also  highly  characteristic. 

In  this  condition,  it  is  claimed,  the  ferric  sulphate  possesses 
qualities  differing  essentially  from  those  attributed  to  it  in 
chemical  text-books,  or  found  in  the  commercial  article.  The 
latter  gives  no  syrupy  solution,  is  of  a  yellow-brown  color,  and 
in  aqueous  solution  is  decomposed  by  boiling,  while  the  prep- 
aration produced  according  to  the  above  method  remains  un- 
decomposed  by  boiling  even  in  a  solution  of  200  to  400  B.  It 
is  further  claimed  that  the  ferric  sulphate  prepared  according 
to  Knapp's  method  is  more  abundantly  absorbed  by  the  skin. 

After  tanning,  the  skins  are  treated  with  fat  solutions  and  a 
so  called  iron  soap.  Greasing  the  skins  by  hand,  hanging  them 
up  in  the  drying-room  and  scraping  off  the  excess  of  fat  is  done 
away  with.  Stearin  and  paraffin  are  suitable  materials  for  the 
fat  solution. 

The  iron  soap  is  separated  in  an  insoluble  form  by  precipi- 
tating soap  solution  with  Knapp's  ferric  salt.  The  iron  soap  pre- 
pared in  this  manner  is  mechanically  fulled  into  the  skin,  a  fulling 
drum  constructed  by  Knapp  being  used  for  the  purpose. 

A  paste  of  iron  soap  is  applied  to  the  skin  with  or  without 
an  addition  of  fatty  emulsions,  or  placed  together  with  the  skins 
in  the  fulling  drum  and  mechanically  fulled  in.  The  skins  are 
dried  at  the  same  time  by  the  current  of  air  passing  through  the 
fulling  drum.  The  new  and  peculiar  features  claimed  for  this 
purpose  by  Knapp  are  as  follows  : 


292 


THE  MANUFACTURE  OF  LEATHER. 


1.  The  preparation  of  the  ferric  salt,  especially  the  treatment 

of  the  ferrous  sulphate  oxidized  by  nitric  acid  by  a 
further  addition  of  the  same  salt. 

2.  The  treatment  of  the  skins  and  hides  with  solutions  of  iron 

and  fat. 

3.  The  use  of  stearin  for  the  above  purpose. 

4.  The  fulling  drum  connected  with  a  fan  by  which  a  current 

of  air  is  forced  into  it. 

5.  The  iron  soap  and  its  use. 

The  advantages  of  this  method  of  tanning  are,  according  to 
Knapp — 

1.  Greater  cheapness  (from  5  to  25  percent.). 

2.  Considerable  saving  of  time,  the  product  being  of  an  equal 

quality  and  durability. 

3.  The  obtaining  of  as  large  a  yield  as  by  tanning  in  the  ordi- 

nary manner. 

4.  The  use  of  a  tanning  material  of  a  constant  chemical  com- 

position, by  which  the  obtaining  of  a  uniform  product  is 
assured. 

The  leather  prepared  by  Knapp's  process  had  a  brown-yellow 
color  closely  resembling  that  of  leather  tanned  by  the  ordinary 
manner.  It  is,  according  to  Knapp,  not  water-proof  but  capa- 
ble of  resisting  water,  meaning  by  this  that  the  leather  does  not 
lose  its  tannin  by  frequent  contact  with  water.  As  far  as  we 
know,  this  process  was  only  used  for  the  preparation  of  sole  and 
belt  leather,  and  we  are  unable  to  say  whether  upper  leather 
was  later  successfully  produced. 

We  will  say  nothing  further  pro  ct  contra  in  regard  to  this 
method. 

Knapp  also  applied  for  an  additional  patent  for  a  somewhat 
different  method  of  preparing  the  ferric  salts.  Instead  of  add- 
ing, as  formerly  described,  nitric  acid  to  a  boiling  solution  of 
ferrous  sulphate,  an  equivalent  quantity  of  sulphuric  acid  and 
sodium  nitrate  is  added  to  the  ferrous  sulphate  solution.  The 
tanning  with  this  is  effected  in  the  same  manner  as  previously 
described,  but  can  also  be  done  by  the  precipitate  which  albu- 


"  CHROME,"  OR  MINERAL  TANNAGE. 


293 


minous  substances,  as  for  instance  that  of  blood,  produce  with 
the  ferric  solution. 

In  the  years  1 880  and  1881,  Heinzerling  obtained  patents  in 
the  United  States,  and  previously  in  other  countries,  for  quick 
tanning  with  chromates,  with  an  addition  of  aluminium  salts, 
sodium  chloride,  etc. 

The  process  is  executed  as  follows : 

The  skins  are  cleansed,  depilated,  and  swelled,  and  placed  in 
a  one-quarter  per  cent,  solution  of  chromic  acid  or  in  a  half  per 
cent,  solution  of  potassium  bichromate,  sodium  bichromate,  or 
magnesium  bichromate  or  other  neutral  bichromates,  or  in  a 
half  per  cent,  solution  of  chromic  salts,  for  instance  chromic 
sulphate.  It  is  advantageous  to  add  to  the  solution  one  per 
cent,  of  alum  or  aluminium  sulphate  or  other  aluminium  salts, 
and  one  per  cent,  of  sodium  chloride.  According  to  their  thick- 
ness the  skins  remain  in  the  solution  a  shorter  or  longer  time ; 
calf-skins,  for  instance,  four  to  six  days,  and  heavy  bullock 
hides  up  to  fourteen  days.  During  this  time  the  solution  is 
successively  concentrated  until  it  contains  as  much  as  6^  per 
cent,  of  chromates,  12  per  cent,  of  alum,  and  10  per  cent,  of 
common  salt. 

The  action  of  tanning  liquors  gradually  increasing  in  strength 
can  also  be  effected  in  a  more  simple  manner  by  placing  the 
skins  successively  in  more  concentrated  solutions  and  allowing 
them  to  remain  a  corresponding  time  in  each  of  the  solutions. 

When  fresh  skins  are  placed  in  the  tanning-liquors,  the  tan- 
ning substance  withdrawn  by  the  skins  taken  out  must  be 
always  supplemented,  the  quantity  required  being  determined 
by  analysis. 

Although  experience  has  shown  that  the  tanning  process  can 
be  executed  without  the  use  of  aluminium  combinations  and  of 
common  salt,  it  is  advantageous  to  employ  them,  since  these 
substances  possess  also  tanning  properties  and  accelerate  the 
process,  and  besides  being  comparatively  cheap,  reduce  the  cost 
of  the  operation. 

If  leather  is  to  be  produced  which  is  to  be  blackened  after 


294 


THE  MANUFACTURE  OF  LEATHER. 


tunning,  2  to  3  per  cent,  of  potassium  ferric-cyanide  or  potas- 
sium ferro-cyanide  is  added  to  the  solution.  These  substances, 
together  with  the  iron  black  applied  later  on,  give  a  deep  dark- 
blue  color  to  the  leather. 

After  tanning  in  the  described  solutions,  the  skins  are  placed 
in  a  4  to  8  per  cent,  solution  of  barium  chloride,  acetate  of  lead, 
or  soap,  which  effects  a  partial  fixing  of  the  tanning  substance 
by  the  latter  forming  with  the  first  insoluble  salts  or  soaps. 

To  effect  a  quicker  absorption  of  the  barium  chloride,  ace- 
tate of  lead,  or  soap,  the  skins,  while  in  the  solutions,  are  vigor- 
ously moved  or  kneaded.  They  are  next  washed,  superficially 
dried  and  stretched,  and,  while  still  feeling  somewhat  moist, 
placed  for  36  hours  in  a  solution  of  stearin,  paraffin,  wax,  rosin, 
colophony,  spermaceti,  or  of  other  hydrocarbons  or  fat,  in 
benzine  or  other  solvents  having  a  similar  effect. 

It  is  advantageous  to  heat  the  solution  containing  fat,  paraffin 
or  other  hydrocarbons  to  96. 8°  F.  in  a  water-bath.  In  place 
of  stearin  or  the  other  substances  mentioned,  a  mass  resembling 
caoutchouc  can  be  used,  which  is  obtained  by  treating  oils 
(linseed  or  rape-seed  oil)  with  10  to  15  per  cent,  of  chloride  of 
sulphur.  If  chromic  acid  is  used  in  tanning,  the  paraffin  em- 
ployed in  the  after-treatment  is  oxidized  by  the  acid,  the  latter 
being  at  the  same  time  reduced  to  chromic  oxide.  The  paraf- 
fin appears  to  become  oxidized  to  an  acid-like  combination 
which  enters  with  the  chromic  oxide,  formed  into  a  combination 
insoluble  in  water,  which  is  firmly  precipitated  upon  the  fibre. 
When  chromates  are  used,  the  chromic  acid  is  split  off  from  the 
chromates  during  the  tanning  process,  either  by  the  skin  itself, 
or,  in  case  aluminium  salts  are  employed,  by  the  sulphuric  acid 
liberated  from  them.  By  the  succeeding  treatment  with  paraf- 
fin, etc.,  the  insoluble  combination  described  above  is  also 
formed.  As  a  proof  of  the  described  action  taking  place  upon 
the  paraffin,  we  would  mention  the  fact  that  the  cut  surface  of 
leather  prepared  according  to  the  described  process  is  at  first 
yellow,  but  becomes  gradually  lighter,  especially  when  exposed 
to  the  light,  and  turns  finally  to  a  nearly  whitish-green.  Metallic 


"  CHROME,"  OR  MINERAL  TANNAGE. 


295 


salts,  for  instance  cupric  sulphate  and  others,  can  be  added  to 
the  solution  of  chromates  formerly  mentioned,  partly  on  ac- 
count of  the  tanning  effect  of  these  salts,  and  partly  in  order  to 
produce  certain  shades  of  color  upon  the  leather. 

The  skins  can  also  be  placed,  either  before  or  after  they  have 
been  treated  with  the  described  tannin  liquors,  in  solutions  con- 
taining vegetable  tannin. 

After  the  skins  have  been  removed  from  the  solutions  of  fat, 
paraffin  or  rosin,  the  leather  intended  for  uppers  and  belts  is 
greased  in  the  same  manner  as  leather  tanned  in  the  usual 
manner,  with  a  mixture  of  tallow,  train  oil,  or  similar  fat  mix- 
tures. After  greasing,  the  fat  is  either  fulled  in  or  allowed  to 
soak  in  by  hanging  the  skins  in  a  moderately  heated  room. 

The  upper  leather  is,  generally  speaking,  curried  in  the  same 
manner  as  leather  tanned  by  the  ordinary  process,  a  few  points 
only  requiring  special  precautions  to  assure  a  fine  product. 

In  preparing  black  grain  leather,  it  is  best  to  blacken  the 
skins  before  placing  them  in  the  fat  solutions.  For  blacking, 
on  account  of  the  yellow  ground  being  more  difficult  to 
blacken,  the  application  must  be  repeated  once  or  twice  oftener 
than  for  leather  tanned  in  the  ordinary  manner. 

If  the  leather  is  to  be  blackened  after  greasing  and  currying, 
the  fat  must  first  of  all  be  thoroughly  removed  by  scouring 
with  dilute  solution  of  soda  or  ammonia,  and  rubbing  with 
pumice  stone  powder,  or  wood  ashes.  The  grain  side  thus 
cleansed  is  then  blackened  with  logwood  extract  or  iron  black. 

Sole  leather  tanned  by  the  above  process  is,  after  removal 
from  the  tanning  liquor,  impregnated  with  solutions  of  fat,  wax, 
or  rosin.    It  is  then  dried  or  rolled. 

In  working  the  upper  and  sole  leather  into  shoes,  the  follow- 
ing directions  should  be  observed  :  In  order  to  be  able  to  last 
the  upper  well,  it  should  be  placed  in  luke-warm  soap-liquor 
for  10  to  12  hours  and  frequently  kneaded.  Lasting  can  only 
be  accomplished  in  the  ordinary  manner  after  the  fluid  has 
thoroughly  permeated  the  grain,  which  is  more  difficult  to  effect 
than  with  leather  tanned  in  the  usual  manner.    Chromium  leather 


296 


THE  MANUFACTURE  OF  LEATHER. 


it  is  claimed  is  more  water-proof.  The  property  of  the  leather 
of  not  stretching  after  having  been  worked,  deserves  special 
attention,  since  a  shoe  made  a  close  fit,  as  is  generally  the  case 
with  leather  tanned  in  the  usual  manner,  is  apt  to  be  too  tight. 

For  sole  leather  to  be  easily  worked  it  is  not  sufficient  to  dip 
it  simply  in  cold  water;  it  should  remain  for  some  time  in  luke- 
warm water. 

Experiments  which  have  been  made  in  regard  to  the  absorp- 
tion of  water  by  leather  tanned  in  the  usual  manner  and  that 
prepared  with  chromates,  have  shown  that  the  latter  absorbs 
water  slower  and  a  smaller  quantity  of  it  than  the  former. 

A  further  advantage  of  chrome  leather  is  that  it  possesses  the 
property  of  losing  less  tannin  by  repeated  treatment  with  cold 
or  warm  water  than  leather  tanned  in  the  usual  manner. 

The  use  of  iron  alum  and  chrome  alum  was  at  one  time  pro- 
posed and  actually  introduced  into  practice.  But  the  use  of 
these  substances  was  soon  abandoned,  as  the  leather  prepared 
in  this  manner  had  no  advantage  over  that  tanned  with  alum 
and  alumina  salts. 

All  the  above-mentioned  methods  of  tanning  have  been  aban- 
doned on  account  of  the  defective  quality  of  the  product  pro- 
duced by  them.  But  this  can  scarcely  be  attributed  to  the 
properties  of  the  tanning  material,  but  rather  to  the  errors  com- 
mitted in  their  preparation.  By  immersing  leather  prepared 
with  these  tanning  materials  in  tan-liquor  it  was  made  closely 
to  resemble  that  tanned  in  the  ordinary  manner. 

While  the  experiments  of  Cavalin,  Knapp,  Pfanhauser  and 
Heinzerling  led  to  no  immediate  practical  results,  they  were, 
nevertheless,  of  immense  value,  as  laying  the  foundation  for 
others,  who  came  after  them,  to  build  upon.  In  seeking  for 
this  mineral  tanning  substance  it  was  necessary  that  the  new 
material  should  possess  certain  characteristics  which  would  in- 
duce tanners  to  use  it;  namely,  it  should  be  obtainable  in  great 
abundance;  it  must  be  as  cheap  or  cheaper  than  tannin;  it 
should  be  quicker  in  its  action,  so  that  time  might  be  saved  ; 
it  should  be  as  simple,  safe  and  easy  in  its  application  as  a  de- 


"CHROME,"  OR  MINERAL  TANNAGE. 


297 


coction  of  tannin  ;  it  should  produce  a  leather  superior  to  that 
made  by  the  older  methods. 

The  salts  of  aluminium,  iron  and  chromium,  either,  alone  or 
in  various  combinations,  were  found  to  be  useful  in  converting 
raw  hides  into  leather,  but  the  great  majority  of  the  processes 
covering  the  use  of  these  metallic  salts  for  tanning  were  found 
to  be  utterly  impracticable,  because  lacking  in  one  or  mere  of 
the  above-named  essential  characteristics.  It  remained,  how- 
ever, for  American  ingenuity  to  solve  the  problem.  Through 
processes  invented  by  Americans,  all  other  metallic  salts  have 
been  eliminated  and  the  application  of  the  salts  of  chromium 
has  been  made  to  fulfill  all  requirements.  The  two  methods 
of  chrome  tanning  now  in  practical  use,  and  by  which  all 
chrome  leather  is  made  both  in  P2urope  and  America,  may  be 
designated  as  the  "two  bath"  process,  patented  by  Augustus 
Schultz,  and  the  "one  bath"  process,  patented  by  Martin  Den- 
nis. The  Schultz  patents  are  owned  by  the  Tannage  Patent 
Company,  of  Philadelphia,  Pa.,  who  issue  licenses  to  tanners  and 
charge  royalties  for  the  use  of  the  process.  The  Dennis  patents 
are  owned  by  the  Martin  Dennis  Chrome  Tannage  Company, 
of  Newark,  N.  J.,  who  manufacture  the  chrome  tannage  material 
under  the  trade-mark  of  "Tanolin"  and  sell  the  material  out- 
right to  tanners  without  licenses  or  royalties. 

A  detailed  description  of  these  two  methods  of  chrome  tan- 
ning is  given  in  another  part  of  this  volume.  In  this  connec- 
tion, however,  a  description,  in  general  terms,  of  the  Schultz 
process  and  the  Dennis  process  and  a  statement  of  what  has 
been  accomplished  in  the  way  of  chrome  tanning  by  these  two 
methods  will  be  of  interest. 

In  the  Schultz  method,  the  skins,  after  being  fully  prepared 
for  tanning,  are  immersed  in  a  bath  containing  a  solution  of 
bichromate  of  potash  and  muriatic  acid.  This  is  called  the 
"  first  bath,"  in  which  the  skins  remain  until  they  have  absorbed 
sufficient  of  the  chromic  acid.  The  skins  are  then  placed  in 
the  "second  bath,"  which  is  a  solution  of  hyposulphite  of 
soda,  to  which  muriatic  acid  is  added.    The  chemical  reaction 


298 


THE  MANUFACTURE  OF  LEATHER. 


in  the  "second  bath"  sets  free  sulphurous  acid,  which  acts  as 
a  reducing  agent  upon  the  chromic  acid  in  the  skin,  forming 
chromic  oxide,  which  unites  with  the  fiber  of  the  skin  convert- 
ing it  into  leather.  The  proportions  of  bichromate  of  potash 
and  acid  in  the  "first  bath"  and  of  hyposulphite  of  soda  and 
acid  in  the  "second  bath"  have  to  be  very  carefully  adjusted 
to  a  given  amount  of  raw  hide  substance,  which  is  determined 
by  weight.  To  learn  these  proportions,  as  applied  to  different 
kinds  of  hides  and  skins,  requires  considerable  experience  ob- 
tained through  practice.  When  Mr.  Schultz  first  endeavored 
to  draw  the  attention  of  tanners  to  his  process  it  was  severely 
criticised  and  was  considered  on  all  sides  to  be  a  difficult,  com- 
plicated and  dangerous  process  of  tanning.  It  was  not  until 
Mr.  Robert  H.  Foederer,  of  Philadelphia,  and  Mr.  Wm.  Zahn, 
of  Newark,  N.  J.,  made  commercial  leather  which  was  consid- 
ered superior  to  any  heretofore  produced,  that  any  serious  con- 
sideration was  given  to  the  Schultz  process.  At  the  present 
time  the  process  is  largely  used  in  the  production  of  glazed  kid 
and  for  certain  classes  of  glove  leather;  in  fact  the  American 
chrome-tanned  glazed  kid  is  conceded  to  be  the  most  beautiful 
fabric  ever  produced  for  use  in  the  making  of  ladies'  shoes. 
Not  only  do  the  American  shoe  manufacturers  use  the  chrome- 
tanned  glazed  kid  almost  exclusively,  but  large  and  increasing 
quantities  of  this  leather  are  being  exported  to  European 
countries. 

By  the  Dennis  "  one  bath  "  process  the  art  of  chrome  tan- 
ning has  been  greatly  simplified.  A  dilute  solution  of  a  basic 
or  oxy-salt  of  chromium  is  used  in  which  the  chromic  oxide  is 
held  so  loosely  that  it  readily  yields  this  oxide  to  the  skins 
placed  in  the  solution.  In  fact  the  skins  absorb  the  chromic 
oxide  from  the  solution  in  the  same  manner  as  the  skins  would 
absorb  tannin  from  a  bark  liquor.  In  the  Dennis  process  the 
skins  are  not  subjected  to  a  drastic  chemical  reaction,  nor  are 
they  exposed  to  the  action  of  corrosive  acids,  which  in  other 
processes  often  produces  irreparable  damage  to  the  resulting 
leather.    Tanolin  is  the  name  given  to  the  Dennis  one-bath 


"  CHROME,"  OR  MINERAL  TANNAGE. 


299 


chrome  tan  liquor,  and  it  is  designed  to  afford  leather  manu- 
facturers an  easy,  cheap  and  reliable  method  of  producing 
chrome  leather.  It  is  offered  to  tanners  in  a  compact,  con- 
venient and  concentrated  form,  all  ready  for  use.  Tanolin  has 
no  smell  and  will  not  even  stain  the  hands  ;  it  is  handled  in  a 
simple,  straightforward  manner,  in  much  the  same  way  as  a 
bark,  gambier  or  sumac  liquor.  Any  tanner  of  ordinary  ex- 
perience can  handle  tanolin  with  confidence  and  safety.  No 
change  or  special  fitting  up  is  required  in  a  tannery  in  order  to 
use  it,  and  the  usual  apparatus  and  appurtenances  found  in  a 
well-appointed  tannery  are  all  that  is  required  for  the  success- 
ful use  of  tanolin. 

The  advantages  obtained  by  the  use  of  tanolin  must  be  ob- 
vious to  any  unprejudiced  tanner,  but  they  are  enumerated 
below  to  give  emphasis  to  the  point ; 

First.  The  tanning  is  accomplished  in  one  bath. 

Second.  The  tan-liquor  is  clean,  without  stain  or  smell,  and 
can  be  handled  by  workmen  without  risk. 

Third.  The  tanning  material  is  all  prepared  for  use,  and  does 
not  require  an  expert  to  prepare  the  tanning  bath. 

Fourth.  The  tanner  can  handle  the  chrome  liquor  as  he  has 
been  accustomed  to  handle  sumac  or  gambier  liquor. 

Fifth.  The  tan  liquor  can  be  modified  in  its  application  so  as 
to  tan  slowly  or  quickly  as  it  is  desired. 

Sixth.  It  can  be  used  successfully  in  paddle  wheels,  revolv- 
ing drums,  or  in  vats  with  rockers. 

Seventh.  The  tan  liquor  does  not  lose  strength,  change  char- 
acter or  turn  sour  on  exposure,  and  can  be  kept  indefinitely. 

Eighth.  The  old  liquors  can  be  used  and  exhausted,  so  that 
great  economy  can  be  attained  in  the  cost  of  tanning. 

Ninth.  The  chrome  leather  is  produced  without  the  risk  at- 
tending the  use  of  corrosive  materials  and  acids  as  in  other 
processes,  and,  therefore,  the  results  obtained  are  more  uniform 
and  reliable. 

Upon  these  and  many  other  considerations  it  is  claimed  for 
the  Dennis  "one-bath"  process  that  it  is  the  easiest,  safest, 


300 


THE  MANUFACTURE  OF  LEATHER. 


cheapest  and  most  reliable  system  of  chrome  tannage  yet 
devised. 

The  Dennis  process,  without  doubt,  offers  to  tanners  a  most 
inviting  field  for  exploitation,  and  one  can  hardly  realize  what 
changes  may  be  wrought  in  the  future  by  this  method  of 
chrome  tanning.  It  is  surprising  what  has  already  been  accom- 
plished with  it  in  its  application  to  the  production  of  various 
kinds  of  leather.  The  author  would  mention  that  he  has  seen 
the  following  varieties  of  leather  tanned  by  this  process,  and  all 
of  them  of  the  very  finest  quality :  Machine  belting,  made  by 
Geo.  F.  Troutwine  &  Co.,  Gloversville,  N.  Y. ;  harness  leather, 
made  by  The  J.  G.  Hurkhamp  Co.,  Fredericksburg,  Va. ;  hard 
sole  leather,  made  by  D.  M.  Easton,  East  Weymouth,  Mass.; 
upper  leather,  made  by  Hayes  &  Co.,  Belvidere,  N.  Y. ;  glove 
leather,  made  by  Brower  &  Dodge,  Gloversville,  N.  J. ;  glazed 
kid,  in  blacks  and  colored,  made  by  Lennox  &  Briggs,  Haver- 
hill, Mass. ;  chamois  leather,  from  fleshers,  made  by  the  Enter- 
prise Chamois  Works,  Philadelphia,  Pa. ;  picker  band  leather, 
made  by  Prakke  Bros.,  Eibergen,  Holland ;  patent  and  enamel 
leather,  made  by  S.  Halsey  &  Son,  Newark,  N.  J.  The  Dennis 
process  is  simple,  cheap,  quick  and  reliable.  In  this  day  of 
enterprise  and  activity  tanners  are  forced  to  leave  old  ruts  and 
to  keep  thoroughly  posted  on  every  new  process  and  improve- 
ment likely  to  prove  of  advantage  and  profit  to  them. 

The  modern  tanner  cannot  stand  still — the  whole  world 
teaches  us  that.  Electricity  is  driving  out  steam  power,  com- 
pressed air  is  likely  to  drive  out  electricity  as  a  power,  and 
aerial  navigation  is  no  longer  a  dream,  but  a  reality.  To  stand 
still  is  to  be  passed  by  more  enterprising  men  and  completely 
distanced  in  the  commercial  race. 

Of  course  tanners  in  embarking  in  the  new  field  of  chrome 
tannage  will  have  to  have  their  wits  about  them. 

Men  who  are  not  practical  in  the  business,  such  as  curriers 
of  bark  leathers,  should  be  replaced  by  men  specially  compe- 
tent for  every  department.  A  superintendent,  thoroughly  prac- 
tical in  every  detail,  should  be  untrammeled  in  his  operations. 


"CHROME,"  OR  MINERAL  TANNAGE. 


30I 


With  competent  men  in  charge,  there  is  no  reason  why  fancy 
colored  chrome,  glazed  calf  and  imitation  kangaroo  should  not 
be  turned  out  with  entire  success  American  morocco  and  kid 
manufacturers  are  at  the  top  of  the  ladder,  and  manufacturers 
of  chrome  and  combination  calf  and  sides  should  adopt  their 
methods.    They  are  worthy  of  emulation. 

Foreign  methods  of  working,  that  is,  foreign  to  the  business, 
have  been  chiefly  responsible  for  failure  in  getting  out  mer- 
chantable  kids.  For  instance,  take  the  question  of  shaving  and 
putting  out  skins.  It  is  a  mistake  to  stick  to  the  old  currier 
style  of  shaving  on  the  wooden  beam-face.  It  has  been  turned 
down  by  the  regular  men  in  the  business  a  century  ago.  Its 
defects  are  not  so  noticeable  in  dull  or  kangaroo  finish  as  in 
glazed  black  or  fancy  colors.  It  is  utterly  impossible  for  a 
shaver  to  do  good  work  on  a  wooden  beam,  from  the  fact  that 
it  cannot  be  kept  in  proper  working  order.  So  long  as  there  is 
any  hand  shaving  to  do,  the  glass  beam-face  is  the  proper  one 
to  use. 

Skins  should  be  put  out  on  a  morocco  table  and  by  a  regu- 
lar morocco  dresser.  It  is  very  important  to  put  out  fancy 
colors,  chrome,  calf  and  imitation  kangaroo  from  calf  and  kip, 
tight. 

Chrome  tannage  is  increasing  rapidly  in  use  and  favor. 
There  is  an  attraction  in  this  method  of  making  leather  that  is 
almost  fascinating.  Many  leading  tanners  have  been  using 
chrome  tannage  for  a  long  time,  but  during  the  past  year  tan- 
ners all  over  the  country  have  been  quietly  experimenting  with 
chrome  liquors  on  upper  and  sole  leathers. 

Chrome  upper,  both  in  black  and  colors,  is  remarkably  tough 
and  pliable.  It  is  astonishing  how  strong  and  supple  even  light 
skins  may  be  made  by  chrome  liquors.  Chrome  tannage  makes 
leather  comparatively  fireproof,  which  is  a  feature  of  much 
value.  During  wet  or  cold  weather  people  are  in  the  habit,  on 
returning  indoors,  of  pushing  their  shoes  near  heat  or  fire. 
Bark-tanned  leathers  are  very  sensitive  to  heat,  and  liable  to 
burn  readily.    Shoe  manufacturers  and  wholesalers  are  fre- 


302 


THE  MANUFACTURE  OF  LEATHER. 


quently  troubled  by  shoes  returned  with  burnt  uppers.  Those 
who  bought  and  wore  such  shoes,  thoughtlessly  placed  them 
near  the  fire,  and  then  found  the  leather  damaged.  Without 
referring  to  the  application  of  heat,  they  boldly  accused  the 
storekeeper  of  selling  them  inferior  shoes,  and  worried  him  into 
replacing  them  with  a  new  pair.  The  storekeeper  in  turn 
passes  the  burnt  shoes  to  the  firm  from  whom  he  bought  them, 
demanding  recompense  or  duplication. 

Chrome-tanned  leathers  may  be  boiled  for  several  minutes 
with  impunity,  or  exposed  to  strong  heat  for  some  time  without 
injury.  The  process  is  not  specially  new,  but  has  been  much 
improved.  Pioneers  made  and  lost  fortunes  in  it.  To-day, 
however,  chrome  tannage  is  much  better  understood,  and  in- 
structions and  material  are  obtainable  by  which  those  previ- 
ously ignorant  of  it  may  be  guided  with  safety  to  success. 

Although  chrome  tannage  has  thus  far  been  applied  chiefly 
to  goatskins,  it  is  becoming  considerably  used  on  kip,  calf,  and 
even  side-leathers.  It  is  beginning  to  compete  with  bark.  Bark 
tanners  are  encouraged  to  experiment  with  chrome,  foreseeing 
many  advantages  in  the  saving  of  labor,  etc.  Chrome  tannage 
takes  shorter  time  and  does  away  with  bark  piling,  cost  of  in- 
surance, interest,  etc.,  on  bark  stacks,  grinding,  leaching,  and 
the  labor  and  expense  connected  with  leach  houses. 

Those  who  are  tanning  sole  leather  by  the  chrome  process 
have  every  reason  to  be  gratified  at  results.  The  pretty  leather 
seems  to  be  ideal  material  for  the  bottoms  of  shoes  for  cycling, 
athletics,  etc.,  being  light  in  weight,  delicate  green  or  greenish- 
blue  color,  very  tough  and  pliable.  Chrome  leather  is  also 
excellent  for  slippers,  Goodyear  insoles,  for  soft  shoes  required 
by  old  people,  and  invaluable  in  hospitals,  etc.,  where  noiseless 
tread  is  necessary. 

While  tanners  are  paying  close  attention  to  chrome,  their 
demands  are  being  met  by  concerns  that  either  furnish  the 
instruction,  or  supply  the  chrome  liquors  ready  for  use. 

The  popularity  of  cycling,  golf  and  other  outdoor  sports  has 
given  marked  impetus  to  the  demand  for  what  are  known  as 


"  CHROME,"  OR  MINERAL  TANNAGE. 


303 


sporting  shoes.  Shrewd  shoe  manufacturers,  foreseeing  the 
broadening  field  of  athletics,  have  prospered  by  studying  the 
requirements  and  supplying  the  wants  of  this  field  rather  than 
sticking  to  the  old  and  familiar  staple  lines.  Those  who  are 
manufacturing  sporting  shoes  seem  quite  satisfied  not  only  with 
what  they  have  done  so  far,  but  with  the  outlook  for  the  future. 
All  who  take  pleasure  in  outdoor  sports  and  recreation  are 
willing  to  pay  a  fair  price  for  the  necessary  boots  and  shoes, 
and  are  not  very  particular  as  to  the  shape  or  trimmings.  The 
pedestrian  or  runner  avoids  "  razor  toes."  Such  men  favor 
common-sense  lasts,  and  do  not  ask  for  changes  in  style,  but 
rather  that  their  shoes  be  strong,  durable  and  comfortable. 

The  growing  enjoyment  of  outdoor  exercise  is  proved  by  the 
fact  that  many  leading  hardware  houses  have  established  de- 
partments for  the  sale  of  sporting  goods,  including  shoes. 
Their  customers,  particularly  those  from  the  country,  like  to 
get  these  supplies  at  one  place,  and  the  enterprising  merchants 
strive  to  accommodate  them.  For  a  long  time  hardware  and 
seed  stores  have  carried  cut  soles,  many  of  them  disposing  of 
quite  a  quantity  . of  leather  in  this  manner  each  year. 

Manufacturers  of  boots  and  shoes  for  sportsmen  and  athletes 
are  fortunate  in  having  to  confine  their  solicitations  either  to  the 
better  class  of  retail  stores  or  other  desirable  distributors.  The 
smaller  shoe  dealers  do  not  expect  any  of  this  kind  of  business. 

It  cannot  be  denied  that  much  of  the  pleasure  on  land  or 
water  may  be  made  or  marred  to  a  considerable  extent  by 
one's  boots  and  shoes.  Consequently,  while  there  may  be 
economies  in  clothing,  active,  healthy  men  and  women  do  not 
grudge  what  might  be  called  liberal  expenditure  in  covering 
their  feet.  The  ever-ready  and  alert  shoe  manufacturer  who 
has  studied  the  art  of  making  the  right  kind  of  shoes  for  cyclers, 
athletes,  hunters,  fishermen,  etc.,  is  finding  his  reward  to-day. 
And  his  trade  will  grow  according  to  the  comfort,  quality  and 
judicious  advertising  of  his  product. 

Some  of  the  leading  sole-leather  tanners,  noting  the  new 
trend  of  trade,  are  studying  to  increase  the  supply  of  chrome 


304 


THE  MANUFACTURE  OF  LEATHER. 


tanned  sole,  as  it  is  apparent  that  this  leather  is  excellently 
adapted  for  the  peculiar  toughness  and  pliability  needed  in 
shoes  for  cycling  and  other  purposes. 

There  is  an  increasing  demand  for  bicycle,  golf,  athletic  and 
sporting  shoes.  The  manufacturers  are  beginning  to  pay  at- 
tention to  fhis  new  feature  of  their  trade,  and  the  result  is  that 
there  are  several  styles  of  such  shoes  now  on  market. 

In  his  advertisement  a  prominent  New  York  dealer  says : 
■"My  lines  of  bicycle  shoes  are  designed  with  the  utmost 
care  for  comfort  and  style,  and  every  important  point  is  con- 
sidered as  carefully  as  in  the  manufacture  of  the  highest  grade 
wheel." 

This  seemed  to  us  putting  it  rather  strong,  and,  in  a  recent 
conversation,  the  advertising  manager  of  the  house  said  to  the 
writer:  "  The  advertisement  states  the  truth,  for  we  do  consider 
every  point  about  the  shoe  with  all  possible  care.  We  are 
trying  to  make  a  reputation  for  our  bicycle  shoes.  We  want 
the  trade  of  bicyclists,  both  men  and  women,  and,  if  we  can 
become  known  as  the  makers  of  the  best  bicycle  shoe,  it 
should  result  in  a  growing  and  profitable  business.  The  time 
to  make  that  reputation  is  at  the  start  and  before  other  makers 
take  the  lead." 

Bicycle,  golf,  athletic  and  sporting  shoes  should  be  soft, 
strong,  fine  and  durable ;  they  should  be  easy  on  the  feet  and 
handsome  in  appearance.  The  sole  leather  for  these  shoes 
should  be  made  from  steer  hides,  and  the  shoes  should  be 
tough,  elastic,  and  noiseless.  Chrome  tannage  seems  to  be  the 
only  way  known  of  treating  the  hides  so  that  these  desirable 
results  can  be  produced. 

TANNING  CALF  OR  GOATSKINS  BY  THE  CHROME  PROCESS. 

The  Martin  Dennis  Chrome  Tannage  Co.  publish  these  di- 
rections for  using  tanolin  on  calf  or  goatskins.  This  is  the 
"one-bath"  process: 

I.  On  removing  the  skins  from  the  bran  drench  it  is  well  to 
mill  them  in  a  drum  in  a  pretty  strong  solution  of  alum  and  salt. 


"CHROME,"  OR  MINERAL  TANNAGE.  305 

The  use  of  the  alum  and  salt,  however,  is  optional.  The  object 
in  using  the  alum  and  salt  is  to  keep  the  skin  open  and  plump,  to 
prevent  them  from  drawing  on  the  grain  and  to  keep  the  skins 
during  the  process  of  tanning  in  such  condition  that  they 
can  be  worked  and  set  out  with  a  slicker  after  being  tanned, 
without  having  that  spring  to  the  leather  which  a  good  many 
complain  of  in  working  and  currying  chrome  leather. 

2.  Take  the  skins  from  the  alum  and  salt  solution,  and  place 
them  in  a  bath  containing  a  3  per  cent,  solution  of  tanolin,  to 
which  a  liberal  quantity  of  common  salt  is  also  added. 

3.  As  the  skins  absorb  the  tanolin,  the  tanning  liquor  will  be- 
come lighter  in  color.  To  strengthen  the  liquor  add  more  of 
the  concentrated  tanolin  to  the  tanning  bath,  a  quart  or  a  gal- 
lon as  the  case  may  be,  but  always  enough  to  maintain  the 
color  of  a  3  to  4  per  cent,  solution.  It  is  advantageous  from  time 
to  time  to  correct  the  tanolin  liquor  by  adding  to  it  slowly  and 
carefully  a  solution  of  sal  soda  prepared  in  the  proportion  of  1 
pound  of  sal  soda  to  3  gallons  of  water.  This  soda  solution 
may  be  added  until  the  tan  liquor  begins  to  appear  cloudy; 
then  stop.  This  procedure  will  render  the  tan  liquor  so  sensi- 
tive that  it  will  yield  to  the  skins  the  whole  of  the  tanning  ma- 
terial. By  correcting  the  liquors  as  above  indicated,  the  old 
liquors  may  be  made  over  and  over  again  by  simply  adding 
more  tanolin  with  each  new  pack,  so  as  to  maintain  the  color 
of  a  3  to  4  per  cent,  solution.  When  the  skins  have  assumed 
a  uniform  greenish  blue  color,  and  by  wringing  the  neck  of  a 
thick  skin  it  wrings  out  dry,  and  by  cutting  a  section  of  the 
part  wrung  out  the  skin  appears  fibrous  throughout,  the  skins 
are  tanned. 

4.  On  removing  the  skins  from  the  tanning  bath,  they  should 
be  rinsed  off  in  clean  water  to  remove  the  adhering  liquor ; 
not  washed  for  any  length  of  time,  but  simply  rinsed  off.  The 
skins  should  then  be  struck  out  on  the  flesh  side  with  a  slicker; 
the  tables  used  for  this  purpose  should  be  perfectly  clean  and 
free  from  any  grease  or  oil,  so  that  the  grain  maybe  protected 
from  any  extraneous  substances,  for  in  this  condition  the  grain 

20 


306 


THE  MANUFACTURE  OF  LEATHER. 


of  the  skins  will  absorb  stain  or  grease  easily  and  quickly,  and 
interfere  afterwards  wirh  the  coloring. 

5.  After  striking  out  the  skins  should  be  shaved,  remember- 
ing during  the  shaving  to  protect  the  grain  from  stain  or 
grease. 

6.  The  shaved  skins  can  then  be  stained,  fat-liquored,  col- 
ored, set  out,  etc.,  dried,  staked  and  finished  in  the  ordinary 
way. 

TANNING  SHEEP  SKINS  BY  THE  CHROME  PROCESS. 

The  Martin  Dennis  Chrome  Tannage  Company  give  the  fol- 
lowing directions  for  preparing  sheep  and  lamb  skins  for  tan- 
ning by  their  one-bath  process  : 

1.  The  skins  should  be  wrung  or  pressed  to  remove  the 
animal  grease,  and  then  milled  in  a  solution  of  common  salt 
and  water  to  open  up  and  soften  the  fibres  of  the  skin. 

2.  If  pickled  skins  are  to  be  tanned,  it  is  better  to  remove  the 
pickle  before  commencing  the  tanning  operation,  with  a  drench 
of  "  C.  T.  Bate,"  or,  if  this  preparation  is  not  at  hand,  with  a 
drench  of  bran  and  salt. 

3.  The  skins  should  then  be  given  a  bath  of  alum  and  salt  in 
the  proportion  of  1  to  2  lbs.  alum  and  about  5  lbs.  salt  to  the 
dozen  skins.  The  use  of  alum  and  salt,  however,  is  optional. 
The  object  in  using  it  is  to  keep  the  skins  open  and  plump,  to 
prevent  them  from  drawing  on  the  grain,  and  to  keep  the  skins 
during  the  process  of  tanning  in  such  a  condition  that  they  can 
be  worked  and  set  out  with  a  slicker  after  being  tanned,  without 
having  the  spring  to  the  leather  already  referred  to.  From 
this  point  the  tanning  of  sheepskins  is  the  same  as  the  tanning 
of  calf  and  goat  skins  above  given. 

SOME  PATENTS  FOR  CHROME  TANNAGE. 

It  is  now  an  established  fact  that  chrome- tanned  leather  has 
secured  a  recognized  place  as  an  important  article  of  pro- 
duction, and  when  its  peculiar  and  superior  qualities  become 
more  generally  known  to  the  public,  the  demand  for  this 
mineral-tanned  leather  will  largely  increase.    Believing  as  we 


"  CHROME,"  OR  MINERAL  TANNAGE. 


307 


do  that  chrome  leather  is  a  thing  that  has  come  to  stay,  and 
feeling  confident  that  the  future  is  full  of  promise  to  the 
tanner  who  masters  the  art  of  producing  this  leather,  we 
have  obtained  the  following  information  regarding  the  Dennis 
"one  bath"  process  of  chrome  tannage,  in  order  that  our  read- 
ers may  become  acquainted  with  one  of  the  methods  of  chrome 
tanning  which  is  already  largely  in  use  and  which  has  found 
favor  with  tanners  all  over  the  world. 

For  four  years  tanolin  has  been  sold  in  the  market  as  a 
tanning  material,  and  during  that  time  it  has  achieved  a  wide 
reputation  and  reached  a  large  sale.  This  is  not  to  be  won- 
dered at,  because  the  various  "two-bath"  methods  of  chrome 
tanning  are  more  or  less  complicated,  perplexing  and  uncer- 
tain, and  the  desirability  of  obtaining  an  easier,  simpler  and 
more  certain  method  was  conceded  on  all  sides.  The  tan- 
olin without  doubt  accomplishes  this,  and  removes  the  difficul- 
ties inherent  in  other  systems  of  chrome  tanning  to  a  remark- 
able degree,  affording  the  tanner  a  method  of  changing  from 
"the  old  to  the  new,"  which  is  simplicity  itself.  It  may  be 
said  that  the  "one-bath"  system  opens  up  a  much  wider  appli- 
cation of  the  chrome  tannage,  and  at  present  it  seems  safe  to 
predict  that  at  no  very  distant  day  nearly  all  classes  of  leather 
will  be  tanned  with  chrome. 

The  German  tanners  have  taken  hold  of  the  matter  of  chrome 
tanning  with  great  earnestness  and  have  applied  it  to  the  pro- 
duction of  a  great  variety  of  leathers.  The  German  is  by  na- 
ture an  investigator  and  is,  moreover,  endowed  with  an  amaz- 
ing degree  of  patience  and  perseverance  ;  and  the  consequence 
is  that  when  he  takes  up  with  a  new  thing  he  turns  it  upside 
down  and  inside  out  until  he  discovers  all  there  is  to  it,  and  if 
it  proves  to  have  merit,  he  is  quick  to  adopt  whatever  may  be 
to  his  profit  and  advantage.  So  it  has  been  with  tanolin,  the 
German  recognizing  from  the  start  that  the  "  one-bath  "  method 
of  chrome  tanning  had  many  advantages  over  the  complicated 
"  two-bath "  system.  The  English  are  also  waking  up  to  the 
possibilities  of  mineral  tannage  and  are  giving  considerable 


3o8 


THE  MANUFACTURE  OF  LEATHER. 


attention  to  it,  though  they  have  not  accomplished  so  much  in 
this  direction  as  the  Germans. 

Until  recently  the  chrome  tannage  has  been  almost  entirely 
confined  to  the  production  of  light  shoe  leathers  from  goat 
skins,  but  since  the  introduction  of  tanolin  nearly  all  sorts  of 
hides  and  skins  have  been  tanned  with  chrome  and  finished  in 
a  great  variety  of  ways  for  almost  all  the  uses  to  which  leather 
is  put.  It  is  interesting  to  note  what  has  already  been  accom- 
plished with  tanolin  by  clever,  enterprising  tanners. 

In  view  of  the  things  already  accomplished,  it  is  difficult  to 
foretell  where  these  new  and  modern  processes  of  tanning  will 
lead  us.  Of  one  thing  we  are  certain,  and  that  is  that  it  brings 
a  benefit  to  all  concerned ;  to  the  tanner,  because  it  enables 
him  to  produce  leather  cheaper  and  quicker;  to  the  consumer 
of  leather,  because  he  is  furnished  with  a  better  and  more  dur- 
able article. 

THE  DENNIS  TANNING- LIQUOR.* 

This  invention  relates  to  a  liquor  to  be  used  in  the  tanning  of 
leather,  and  is  described  by  Mr.  Dennis  as  follows: 

It  consists  of  a  novel  composition  of  matter  in  a  liquor  for 
tanning  hides  or  skins  in  the  method  known  as  chrome  tanning, 
and  the  method  of  making  the  same. 

In  an  application  filed  by  me  on  the  3d  day  of  October, 
1892,  Serial  No.  447,695,  I  have  described  and  claimed  the  use 
of  this  liquor,  which  is  the  subject  matter  of  this  application,  in 
tanning  hides,  and  this  application  has,  therefore,  no  reference 
to  the  methods  of  using  this  liquor,  but  relates  solely  to  the 
composition  of  the  liquor  itself  and  the  method  of  making  it. 

It  has  long  been  known  that  chrome  oxide  has  the  property 
of  combining  with  the  hide  gelatine  to  form  an  insoluble  and 
non-putrescent  body,  and  is,  therefore,  capable  of  converting 
hides  into  leather.  It  has  only  been  during  the  last  few  years, 
however,  that  commercial  leather  has  been  made  by  the  so- 
called  chromic  tannage,  and  there  is  still  much  room  for  im- 
provement. 

*  Patented  by  Martin  Dennis,  Newark,  N.  J.    United  States  Patent,  No.  511,411. 


'  CHROME,"  OR  MINERAL  TANNAGE. 


309 


The  difficulty  standing  in  the  way  of  the  use  of  chromic 
oxide  as  a  tanning  agent  has  been  its  insolubility  in  water,  and 
the  consequent  difficulty  in  getting  the  chromic  oxide  into  inti- 
mate contact  with  the  hide  or  skin  to  be  tanned.  Attempts 
have  been  made  to  overcome  this  difficulty  by  the  use  of 
chromic  alum  as  a  tanning  agent,  but  without  practical  success. 
When  chromic  alum  is  used  deoxidation  or  reduction  is  un- 
necessary, since  the  chromium  exists  in  the  alum  in  the  form  of 
an  oxide  ;  but  as  chromic  alum  is  a  very  stable  body  and  gives 
up  its  chromic  oxide  with  great  difficulty,  the  process  of  fixing 
the  hide  gelatine  by  its  use  is  exceedingly  slow,  unsatisfactory 
and  expensive.  This  difficulty  has  in  a  measure  been  overcome 
in  some  processes,  by  impregnating  the  hide  or  skin  with 
chromic  acid  and  then  reducing  this  chromic  acid  to  chromic 
oxide  in  the  substance  of  the  hide  by  the  use  of  some  reducing 
agent,  as,  for  example,  sulphurous  or  oxalic  acid,  sulphureted 
hydrogen  or  protosulphate  of  iron.  The  chromic  acid  in  these 
processes  is  usually  introduced  into  the  hides  orskins  by  immers- 
ing them  in  a  bath  to  which  bichromate  of  potassium  and  a 
strong  acid  like  hydrochloric  acid  have  been  added.  Chromic 
acid,  however,  is  a  powerful  oxidizing  and  corrosive  agent  and 
invariably  docs  more  or  less  injury  to  the  hide  or  skin,  and,  un- 
less it  is  handled  with  very  great  skill  and  caution,  will  produce 
leather  which  will  become  hard  and  crack,  and  exhibit  other  de- 
fects. In  fact  the  utmost  care  and  experience  often  fail  to  pre- 
vent the  finished  leather  from  showing  the  destructive  effect  of 
this  powerful  corrosive  agent.  One  of  the  probable  causes  of 
the  deterioration  of  leather  made  by  the  use  of  chromic  acid  is 
that  chromic  acid  itself  appears  to  enter  to  a  greater  or  less  ex- 
tent into  some  sort  of  combination  with  the  hide  gelatine,  in 
which  combination  it  is  not  wholly  reduced  to  chromic  oxide  by 
the  sulphurous  acid  or  other  reducing  agent  employed,  but 
after  the  leather  is  finished  and  placed  upon  the  counter  or 
manufactured  into  shoes,  the  oxidizing  and  destructive  effects 
of  the  chromic  acid  become  manifest  by  its  losing  its  strength 
and  suppleness  and  becoming  hard  and  brittle  and  papery  to 


THE  MANUFACTURE  OF  LEATHER. 


the  touch.  The  unsatisfactory  action  of  chromic  alum  in  tan- 
ning and  the  destructive  effect  of  the  chromic  acid  upon  the 
fiber  of  the  hide  and  skin,  therefore,  renders  it  highly  desirable 
to  employ  some  method  of  chrome  tanning  which  will  be 
quicker  and  cheaper  and  more  satisfactory  than  the  use  of 
chromic  alum,  and  which  will  not  necessitate  the  bringing  of  the 
hide  or  skin  into  contact  with  these  strong  and  corrosive  acids. 
The  object  of  my  experiments  was,  therefore,  to  discover  some 
method  of  introducing  chromic  oxide  to  the  hide  or  skin,  to  be 
tanned  in  a  water-soluble,  neutral  and  unstable  combination, 
that  is,  to  discover  some  chromic  oxide  compound  soluble  in 
water, "in  which  the  chromic  oxide  would  be  held  loosely,  that 
is,  in  an  unstable  combination,  and  which  compound,  when  dis- 
solved, would  be  practically  neutral,  and  I  have  succeeded  in 
doing  this  by  my  invention,  which  I  will  now  describe. 

It  is  well  known  that  when  to  solutions  of  a  number  of  the 
normal  salts  of  chromium  is  added  a  quantity  of  a  more  power- 
ful base,  a  part  of  the  acid  which  was  combined  with  the  chro- 
mium base  is  taken  away  and  the  chromium  base  is  left  in  a 
combination  which  may  be  regarded  as  basic,  that  is,  contain- 
ing two  or  more  equivalents  of  the  metallic  base  or  oxide  to 
one  of  the  acid,  and  when  in  this  condition  the  excess  of  the 
metallic  base  or  oxide  over  what  the  acid  would  hold  in  the 
normal  salt  is  readily  yielded  to  any  body  having  an  affinity  for 
it;  that  is,  the  excess  of  the  metallic  base  over  what  would  be 
present  in  the  normal  salt  is  held  in  an  unstable  combination 
with  the  normal  salt.  While  this  is  a  well-known  chemical  fact, 
it  was  not  known  prior  to  my  discovery  or  invention  that  any 
commercial  use  could  be  made  of  this  chemical  property  of  the 
salts  of  chromium  in  chrome  tanning. 

In  preparing  my  tanning  liquor  according  to  this  invention,  I 
utilize  this  property  of  chromium  salts.  I  have  found  chloride 
of  chromium  best  adapted  for  my  purposes,  although  other  in- 
organic salts  of  chromium  may  be  used  with  more  or  less  suc- 
ces,  and  I  prefer  to  use  chloride  of  chromium  in  practicing  my 
invention,  and  shall  use  it  hereinafter  in  illustrating  the  same. 


"CHROME,"  OR  MINERAL  TANNAGE.  3  I  I 

In  practicing  my  invention,  I  first  prepare  a  solution  of  com- 
mon chloride  of  chromium.  This  may  be  done  by  dissolving 
the  commercial  oxide  of  chromium  in  commercial  hydrochloric 
acid,  which  has  been  diluted  with  an  equal  bulk  of  water,  care 
being  taken  to  use  more  chromic  oxide  than  the  acid  will  take 
up,  in  order  that  the  resulting  solution  may  be  as  nearly  neutral 
as  possible.  About  eight  ounces  of  the  commercial  acid  is 
sufficient  to  dissolve  a  pound  of  commercial  oxide  of  chro- 
mium. When  this  reaction  is  complete  I  have  the  normal  salt 
of  chromium,  known  as  the  chloride  of  chromium,  in  solution. 
In  order  to  render  this  normal  salt  of  chromium  a  basic  salt,  I 
add  slowly  and  carefully  to  this  solution  a  solution  of  a  more 
powerful  base,  continuing  the  addition  to  a  point  where  the 
normal  salt  has  been  practically  rendered  entirely  basic.  This 
point  will  differ  in  different  cases,  depending  in  a  measure  on 
the  strength  of  the  solutions,  but  the  addition  should  not  be 
carried  beyond  the  point  at  which  the  oxide  of  chromium  be- 
gins to  precipitate,  and  the  amount  of  base  to  be  added  can  be 
readily  ascertained  in  each  case  by  making  a  small  experimen- 
tal mixture.  I  may  use  for  this  more  powerful  base  any  of  the 
caustic  alkalies  or  the  carbonates  of  these  alkalies,  but  I  prefer 
to  use  either  caustic  soda  or  the  carbonate  of  soda,  or,  as  the 
latter  is  known  in  trade,  "sal  soda."  And  when  this  is  used  it 
may  be  added  until  rapid  effervescence  ceases.  It  usually  takes 
about  half  a  pound  of  sal  soda  crystals  to  each  pound  of 
chromic  oxide,  dissolved  as  above.  When  this  reaction  is 
complete,  it  will  be  found  that  the  carbonate  of  sodium  has 
changed  the  normal  chloride  of  chromium  into  an  oxy  or  basic 
chloride  of  chromium.  This  may  be  considered  as  consisting 
of  a  normal  chloride  of  chromium  and  chromic  oxide  in  a  water- 
soluble  combination,  free  chromic  oxide,  hydrated  or  otherwise, 
being  insoluble  in  water.  This  oxy  or  basic  chloride  of  chro- 
mium is  a  very  unstable  body,  giving  up  its  excess  of  chromium 
oxide  whenever  there  is  presented  to  it  a  body  or  substance  for 
which  chromic  oxide  has  an  affinity,  as,  for  instance,  hide  gel- 
atine.   There  exists  also  in  this  solution,  when  the  last  reaction 


312 


THE  MANUFACTURE  OF  LEATHER. 


is  completed,  a  quantity  of  chloride  of  sodium  formed  by  the 
union  of  a  part  of  the  acid  which  was  in  combination  with  the 
chromium  in  the  normal  salt  of  chromium  with  the  sodium  base 
of  the  carbonate  of  sodium.  This  chloride  of  sodium  serves 
the  useful  purpose  of  preventing  the  grain  of  the  leather  from 
drawing  under  the  astringent  effect  of  the  chromium  salt  and 
facilitates  the  tanning  action,  and  to  further  effect  these  pur- 
poses I  also  add  to  this  solution  a  few  pounds  more  of  chloride 
of  sodium  (common  salt).  When  I  use  any  of  the  alkalies  or 
alkaline  carbonates  that  do  not  contain  soda,  I  prefer  to  add  to 
the  solution  common  salt.  When  this  has  been  done,  my  tan- 
ning liquor  is  complete  and  ready  for  use  in  the  manner  indi- 
cated in  my  aforesaid  application. 

I  am  aware  that  others  have  added  carbonate  of  sodium  to  the 
solution  of  a  chromium  salt,  but  in  all  cases  where  this  has  been 
done,  only  so  much  carbonate  of  sodium  has  been  added  as 
would  serve  to  take  up  the  free  acid  in  the  solution  of  the  chro- 
mium salt,  and  thereby  neutralize  the  solution;  and  in  no  case 
has  carbonate  of  sodium  been  added  to  the  solution  of  the  chro- 
mium salt  in  an  amount  sufficient  to  effect  or  change  the  chro- 
mium salt  in  any  particular,  or  for  that  purpose,  while  in  my 
invention  that  is  one  of  the  principal  objects  of  adding  the  car- 
bonate of  sodium,  as  my  solution  is  practically  neutral  before 
its  addition. 

The  tanning  liquor  produced  by  this  invention  is  cheaper  and 
more  quickly  and  easily  used  than  a  liquor  made  from  chromic 
alum  ;  is  practically  neutral,  has  no  corrosive  action  on  the 
hides,  and  is  free  from  all  offensive  odors,  in  these  particulars 
as  well  as  others  being  a  marked  improvement  on  all  known 
tanning  liquors. 

In  the  foregoing  specification  and  in  the  claims  to  follow,  the 
term  basic  is  meant  to  include  metallic  salts,  which  contain 
more  than  one  equivalent  of  the  metallic  base  to  one  equiva- 
lent of  the  acid,  as  above  described;  and  in  the  claims,  the  term 
carbonate  of  sodium  is  meant  to  include  its  chemical  equiva- 
lents for  the  purpose  specified. 


"  CHROME,"  OR  MINERAL  TANNAGE.  313 

The  word  "  tanning"  is  meant  to  include  all  methods  of  fixing 
or  rendering  insoluble  the  so-called  gelatine  of  the  hides  or 
skins,  for  the  purpose  of  converting  them  into  leather. 

My  invention  consists  broadly  in  a  method  or  process  of 
making  a  tanning  liquor  containing  a  basic  or  oxy-inorganic 
salt  of  chromium  and  the  product  of  that  process. 

Specifically,  it  includes  a  method  or  process  of  making  a  tan- 
ning liquor  containing  a  basic  or  oxy-chloride  of  chromium 
and  chloride  of  sodium,  and  the  product  of  that  process. 

THE  DENNIS  PROCESS  OF  TANNING  LEATHER.* 

This  invention  relates  to  the  manufacture  of  leather. 

It  consists  of  a  novel  method  of  fixing  the  so-called  gelatin 
of  the  hide  or  skin  by  means  of  a  metallic  oxide,  and  has  for  its 
object  the  cheapening  and  simplifying  of  the  process  of  making 
mineral  tanned  leather,  as  well  as  the  improvement  of  the 
manufactured  product,  and  is  described  as  follows  by  Mr. 
Dennis  : 

It  has  long  been  known  that  chromic  oxide  has  the  property 
of  combining  with  hide  gelatin  to  form  insoluble  and  non- 
putrescent  body,  and  is,  therefore,  capable  of  converting  hides 
into  leather.  It  has  been  but  a  few  years,  however,  that  com- 
mercial leather  has  been  made  by  the  so-called  chromic  tan- 
nage, and  there  is  still  much  room  for  improvement  in  this 
kind  of  leather  as  placed  at  present  on  the  market.  In  my 
process  chromic  oxide  is  presented  to  the  hide  gelatin  in  the 
state  of  a  soluble  combination  in  which  it  is  so  loosely,  held 
that  it  is  readily  given  up  to  the  gelatin,  rendering  the  fixing  of 
the  latter  both  rapid  and  complete.  The  soluble  combination 
which  I  use  is  designated  by  chemists  as  a  basic  or  oxy  salt. 
When  to  solutions  of  a  number  of  the  normal  salts  of  chro- 
mium is  added  a  quantity  of  a  more  powerful  base,  a  part 
of  the  acid  which  was  combined  with  the  chromium  base  is 
taken  away  and  the  base  is  left  in  a  combination  which  may  be 
regarded  as  basic,  that  is,  containing  two  or  more  equivalents 

*  Patented  by  Martin  Dennis,  Newark,  N.  J.    United  States  Patent,  No.  495,028. 


314 


THE  MANUFACTURE  OF  LEATHER. 


of  the  metallic  base  or  oxide  to  one  of  the  acid.  In  this  case 
the  excess  of  metallic  base  over  what  the  acid  would  hold  in  the 
normal  salt  is  readily  yielded  to  any  body  having  an  affinity  for 
it.  The  effectiveness  of  my  method,  as  far  as  the  mere  fixing 
of  the  gelatin  is  concerned,  lies  in  bringing  the  latter  in  con- 
tact, in  a  neutral  or  nearly  neutral  solution,  with  a  chromic 
oxide  so  held  as  to  be  readily  taken  up  by  the  gelatin.  This 
result  is  accomplished  by  solutions  of  the  combinations  which 
I  have  called  basic  salts  of  chromium,  and  they  furnish  the 
only  practicable  means  of  presenting  to  the  hide  gelatin, 
chromic  oxide  in  soluble  form  and  yet  not  in  stable  combina- 
tion with  acids.  When  hides  or  skins,  properly  prepared,  are 
treated  with  a  solution  of  one  of  these  basic  chromic  salts  the 
gelatin  quickly  takes  up  the  excess  of  the  chromium  base,  (in 
combination  with  which  it  is  insoluble,)  and  leaves  only  the  re- 
maining normal  salt  in  solution. 

Attempts  have  been  made  to  use  chromic  alum  for  convert- 
ing hides  into  leather,  but  without  practical  success.  When 
chromic  alum  is  used,  deoxidation  or  reduction  is  unecessary, 
since  the  chromium  exists  in  the  alum  in  the  oxide  form  ;  but 
as  chromic  alum  is  a  very  stable  body,  and  gives  up  its  chromic 
oxide  with  great  difficulty,  the  process  of  fixing  the  hide  gelatin 
by  its  means  is  exceedingly  slow  and  unsatisfactory. 

The  central  idea  upon  which  the  practicable  methods  of 
chromic  tannage,  other  than  mine,  are  based,  is  to  impregnate 
the  hide  or  skin  with  chromic  acid,  and  then  to  reduce  this 
acid  to  chromic  oxide  in  the  substance  of  the  hide,  by  means  of 
some  reducing  agent,  for  example  sulphurous  or  oxalic  acid, 
sulphureted  hydrogen  or  protosulphate  of  iron.  The  chromic 
acid  is  usually  introduced  into  the  hides  or  skins  by  immersing 
them  in  a  bath,  to  which  bichromate  of  potassium  and  a  strong 
acid  like  hydrochloric  have  been  added.  Chromic  acid,  how- 
ever, is  a  powerful  oxfdizing  and  corrosive  agent,  and  invariably 
does  more  or  less  injury  to  the  hide  or  skin,  and  unless  it  is 
handled  with  very  great  skill  and  caution  will  produce  leather 
which  will  become  hard  and  crack  and  exhibit  other  defects. 


"  CHROME,"  OR  MINERAL  TANNAGE. 


315 


In  fact  the  utmost  care  and  experience  often  fail  to  prevent 
the  finished  leather  from  showing  the  destructive  effect  of  this 
powerful  chemical  agent. 

One  of  the  probable  causes  of  the  deterioration  of  leather 
made  by  the  use  of  chromic  acid  is,  that  chromic  acid  itself 
appears  to  enter  to  a  greater  or  less  extent  into  some  sort  of 
combination  with  the  hide  gelatin,  in  which  combination  it  is 
not  wholly  reduced  to  chromic  oxide  by  the  sulphurous  acid  or 
other  reducing  agent  employed,  but  after  the  leather  is  finished 
and  placed  upon  the  counter  or  manufactured  into  shoes,  the 
oxidizing  and  destructive  effects  of  the  chromic  acid  become 
manifest,  by  losing  its  strength  and  suppleness  and  becoming 
hard  and  brittle  and  papery  to  the  touch. 

It  is  true  that  the  above  method,  as  far  as  fixing  the  gelatin  is 
concerned,  although  it  is  done  in  acid  solution,  is  very  effective. 
In  fact  it  is,  outside  of  mine,  the  only  practical  way  known  of 
occomplishing  that  result.  This  effectiveness  is  due  to  the  fact 
that  chromic  oxide  (which  is  the  real  fixing  agent)  is  formed 
by  the  reduction  of  the  chromic  acid  while  in  actual  contact 
with  the  hide  gelatin.  Therefore  the  gelatin  can  take  up  the 
chromic  oxide  while  in  the  so-called  "  nascent"  state,  and  thus 
accomplish  in  a  solution,  what  it  could  not  easily  do  if  the 
oxide  were  not  formed  in  direct  contact  with  it;  for  instance, 
as  when  the  hide  is  treated  with  an  acid  or  even  neutral  solu- 
tion of  a  normal  salt  of  chromium.  But  the  destructive  action 
of  chromic  acid  on  the  fiber  of  the  hide  or  skin  (particularly 
when  the  highest  skill  is  not  employed)  renders  it  extremely 
desirable  to  use  a  method  in  which  the  hide  is  not  exposed  to 
the  action  of  chromic  acid  or  other  destructive  chemical  agent, 
or  to  intensely  acid  solutions  of  any  kind,  but  in  which  the 
chromic  oxide  is  brought  in  contact  with  the  hide  gelatin  in  a 
nearly  neutral  and  mild  solution,  and  yet  in  a  form  in  which  it 
can  be  easily  and  quickly  taken  up.  All  this  is  accomplished 
by  my  method,  which  I  will  now  describe. 

The  salt  of  chromium  which  I  have  found  well  adapted  for 
my  purpose  is  the  chloride,  although  other  salts  might  be  used, 


3i6 


THE  MANUFACTURE  OF  LEATHER. 


and  this  I  use  to  illustrate  my  process  in  the  following  descrip- 
tion :  I  first  prepare  a  solution  of  common  chloride  of  chro- 
mium. This  may  be  done  by  dissolving  the  pigment  known  as 
chrome  green,  and  which  is  hydrated  oxide  of  chromium,  in 
commercial  hydrochloric  acid  which  has  been  diluted  with  an 
equal  bulk  of  water,  care  being  taken  to  use  more  chromic 
oxide  than  the  acid  will  take  up,  in  order  that  the  resulting 
solution  may  be  as  nearly  neutral  as  possible.  About  eight 
ounces  of  the  commercial  acid  are  sufficient  to  dissolve  a  pound 
of  commercial  hydrated  oxide  of  chromium.  To  this  solution 
of  chloride  of  chromium  I  add  slowly  and  carefully  a  solution 
of  a  more  powerful  base,  and  for  which  purpose  I  prefer  car- 
bonate of  sodium,  or  as  it  is  known  in  the  trade,  "sal  soda," 
until  precipitation  of  chromic  hydrate  begins,  or  if  carbonate 
of  sodium  is  used,  until  rapid  effervescence  ceases.  It  usually 
takes  about  one-half  pound  of  sal  soda  crystals  to  each  pound 
of  chromic  oxide  dissolved  as  above.  I  now  have  a  nearly 
neutral  solution  of  oxy  or  basic  chloride  of  chromium.  It  may 
be  considered  as  consisting  of  the  normal  chloride  of  chromium 
and  chromic  oxide  in  soluble  combination  (free  chromic  oxide, 
hydrated  or  otherwise,  being  insoluble  in  water),  and  a  quantity 
of  chloride  of  sodium  formed  by  the  union  of  a  part  of  the  acid 
which  was  in  combination  with  the  chromium,  with  the  sodium 
base  of  the  carbonate  of  sodium,  and  which  also  serves  a  useful 
purpose,  which  will  be  mentioned  later  on.  The  hides  or  skins, 
after  having  been  suitably  prepared  by  soaking,  liming,  unhair- 
ing,  bating,  washing,  &c,  are  immersed  in  the  solution  of  the 
oxy  or  basic  chloride  of  chromium  prepared  as  above,  and  of  a 
strength  of  about  three  gallons  of  the  concentrated  solution  to 
one  hundred  gallons  of  water.  To  the  solution  is  also  added, 
besides  that  formed  by  adding  carbonate  of  sodium  to  the  solu- 
tion of  chloride  of  chromium,  a  few  pounds  more  of  chloride  of 
sodium  (common  salt)  for  the  purpose  of  preventing  the  grain 
of  the  leather  from  drawing  under  the  astringent  effect  of  the 
chromic  salt,  and  to  facilitate  the  tanning  action.  The  treat- 
ment of  the  hides  or  skins  in  the  above  solution  is  accomplished 


CHROME,"  OR  MINERAL  TANNAGE. 


317 


in  a  "paddle"  or  other  equivalent  apparatus,  as  it  is  quite 
necessary  that  they  be  frequently  moved  in  order  that  the 
action  of  the  chromic  salt  may  be  uniformly  distributed.  Ac- 
cording to  the  thickness  of  the  skins  and  the  strength  of  the 
solution,  this  tanning  process  requires  from  about  ten  to  forty- 
eight  hours.  Ordinary  goat  skins  for  the  so-called  dongola 
leather  do  well  by  running  them  in  the  paddle  during  the  day, 
then  allowing  them  to  stand  over  night  in  the  liquor,  and  run 
the  paddle  about  an  hour  in  the  morning,  when  the  skins  will 
be  found  well  tanned.  The  strength  of  the  chromic  solution 
may  be  varied  according  to  the  thickness  of  the  skins,  and  may 
be  strengthened  from  time  to  time  during  the  tanning  operation 
if  necessary.  After  the  absorption  of  chromic  oxide  has  ceased, 
and  all  the  gelatin  of  the  hide  has  been  rendered  insoluble  by 
its  combination  with  the  chromic  oxide,  which  condition  is 
readily  recognized  by  one  familiar  with  leather  making,  the 
skins  are  washed  in  clean  water,  and  are  then  agitated  in  a  bath 
containing  finely-divided  carbonate  of  calcium  or  its  equivalent. 

Instead  of  carbonate  of  calcium,  carbonate  of  barium  or  the 
carbonates  of  lead,  zinc,  etc.,  may  be  used.  When  carbonate 
of  calcium  is  used,  the  form  known  in  commerce  as  whiting  is 
well  adapted.  The  object  of  agitating  the  skins  with  these  car- 
bonates, which  are  insoluble  in  water,  is  that  every  kind  of  acid 
present  may  be  neutralized  without  subjecting  the  skins  to 
the  action  of  an  alkaline  bath.  The  skins  may  now  be  again 
washed,  after  which  they  are  ready  for  the  so-called  fat-liquor, 
for  drying  previous  to  dyeing,  or  for  any  other  of  the  processes 
belonging  to  the  currier's  art. 

As  my  invention  does  not  appertain  to  the  beam-house  work, 
by  which  the  hides  or  skins  are  prepared  for  tanning,  and 
which  would  be  substantially  the  same  for  my  process  as  for 
any  other  method  of  tanning  or  tawing,  I  will  not  specify  any 
particular  procedure  for  that  part  of  the  tanner's  work.  Neither 
is  it  necessary  to  give  directions  as  to  the  treatment  of  the 
skins  after  they  are  removed  from  the  bath  of  suspended  car- 
bonate of  calcium,  for  it  is  as  various  as  the  different  uses  to 


3i8 


THE  MANUFACTURE  OF  LEATHER. 


which  leather  is  put,  and  does  not  belong  to  the  realm  of  tan- 
ning proper,  with  which  alone  my  invention  has  to  do. 

Among  the  advantages  possessed  by  my  method  may  be 
mentioned  the  following: 

First,  The  tanning  or  fixing  of  the  gelatin  is  effected  entirely 
in  one  bath,  instead,  as  in  the  old  methods,  of  impregnating  the 
skins  with  a  chromic  acid  in  one  bath,  and  then  reducing  the 
chromic  acid  to  chromic  oxide  in  another  bath.  Thus  the  labor 
of  one  handling  is  saved. 

Second,  The  skins  are  not  exposed  to  the  destructive  action 
of  chromic  acid,  whereby  the  leather  is  stronger,  has  much  more 
suppleness  which  it  long  preserves,  shows  a  better  grain,  and 
does  not  become  tinny  or  papery,  as  compared  with  the  pro- 
duct of  the  ordinary  method  of  chromic  tannage. 

Third,  There  are  no  offensive  or  suffocating  smells  evolved, 
as  when  in  the  ordinary  methods  the  chromic  acid  is  reduced 
to  chromic  oxide  by  the  use  of  sulphurous  acid  or  sulphureted 
hydrogen. 

Fourth,  Since  my  tanning  bath  is  entirely  non-corrosive,  there 
is  no  danger  of  allowing  the  skins  to  remain  in  it  too  long,  and 
not  nearly  so  much  skill  and  care  are  necessary  as  in  the  old 
methods. 

Fifth,  Not  only  is  there  a  saving  in  labor  in  my  process,  but 
my  tanning  bath  is  much  cheaper  than  those  of  the  old  meth- 
ods, since  the  chromic  oxide  in  my  tanning  bath  costs  much 
less  as  prepared  by  me  than  as  prepared  from  bichromate  of 
potassium  and  a  reducing  agent  in  the  old  methods. 

Sixth,  The  tanning  is  effected  in  my  process  in  a  bath, 
which  is  not  strongly  acid,  as  is  always  the  case  in  the  old 
methods,  in  which  chromic  acid  is  employed.  This  nearly 
neutral  bath  is  of  great  advantage  to  the  skins,  and  naturally 
assists  the  currier  in  the  subsequent  work  of  dyeing  and  finish- 
ing the  leather. 

In  the  foregoing  specification  and  in  the  claims  to  follow,  the 
term  basic  is  meant  to  include  metallic  salts,  which  contain 
more  than  one  equivalent  of  the  acid,  as  above  described,  and 


"CHROME,"  OR  MINERAL  TANNAGE.  319 

in  the  claims,  the  terms  carbonate  of  calcium  are  meant  to  in- 
clude their  chemical  equivalents  for  the  purpose  specified. 

The  word  "  tanning"  is  meant  to  include  all  methods  of  fixing 
or  rendering  insoluble  the  so-called  gelatin  of  the  hides  or  skins 
for  the  purpose  of  converting  them  into  leather. 

The  gist  of  my  invention  consists  broadly  in  the  use,  as  a 
tanning  agent,  of  a  basic  or  oxy  salt  of  chromium.  Specifically 
it  includes  the  use  as  a  tanning  agent,  a  basic  or  oxy-chloride 
of  chromium.  It  also  includes  a  tanning  bath  prepared  by 
adding  to  a  solution  of  chlorfde  of  chromium,  carbonate  of 
sodium,  or  its  equivalent,  until  the  chromium  salt  is  rendered 
basic.  Further,  it  includes  the  use  of  a  bath  for  tanning  con- 
taining both  basic  chloride  of  chromium  and  chloride  of  so- 
dium. And  lastly,  it  includes  the  process  of  subjecting  hides 
or  skins,  in  which  the  gelatin  has  been  fixed  by  treatment  with 
oxy  or  basic  chloride  of  chromium,  to  the  action  of  a  neutraliz- 
ing bath  of  suspended  carbonate  of  calcium. 

We  are  aware  that  by  publishing  the  Dennis  patents  in  full 
we  have  had  to  make  many  repetitions,  but  this  could  not 
be  avoided,  as  we  wished  to  make  the  chrome  tannage  fully 
understood,  even  if  we  have  had  to  resort  to  tautology  in 
doing  it. 

F.  E.  Atteaux  &  Co.,  Boston,  Mass.,  Sager  Chadwick,  Phila- 
delphia, Pa.,  Samuel  P.  Sadtler,  Philadelphia,  Pa.,  George  W. 
Adler,  who  sold  his  patent  to  the  Eureka  Tannage  Co.,  Phila- 
delphia, Pa.,  Hugo  Schweitzer,  New  York,  N.  Y.,  have  all  re- 
cently invented  one-  and  two-bath  processes  of  chrome  tannage. 

The  patents  issued  to  Augustus  Schultz  and  William  Zahn 
are  given  in  full  in  the  next  chapter. 

CHARACTERISTICS  OF  CHROME  LEATHER. 

Chrome  leather  has  special  and  peculiar  qualities  which  dis- 
tinguish it  from  all  other  kinds  of  leather,  and  these  special 
features  cause  it  to  be  a  superior  fabric  for  all  the  purposes  for 
which  leather  is  used.  It  has  been  often  stated  that  chrome 
leather  is  waterproof,  but  this  is  not  a  proper  term  to  use  in 


320 


THE  MANUFACTURE  OF  LEATHER. 


connection  with  it;  it  should  more  properly  be  called  non- 
absorbent.  All  kinds  of  leather  produced  with  tannin  absorb 
water  readily,  like  a  sponge,  while  chrome  leather  does  not 
absorb  the  water  but  resists  it  or  sheds  it,  like  the  feathers  of  a 
duck;  in  fact  it  is  a  difficult  matter  to  thoroughly  wet  through 
chrome  leather  when  it  is  once  dry.  Again,  water  and  air  are 
the  agencies  in  nature  which  promote  decomposition  and  de- 
cay, and  as  tannin  and  hide  substance  are  both  organic  mater- 
ials, and  when  combined,  as  is  the  case  in  bark-tanned  leather, 
and  subjected  to  a  process  of  wetting  and  drying,  such  leather 
will  eventually  but  surely  deteriorate  and  become  rotten. 

Chrome  leather,  on  the  other  hand,  being  a  combination  of 
an  inorganic  material  with  the  hide  substance,  and  subjected  to 
the  same  process  of  wetting  and  drying,  shows  no  effect  what- 
ever; in  fact,  the  oftener  chrome  leather  is  wet  and  dried  the 
softer  and  more  flexible  it  becomes.  Even  subjecting  it  to 
boiling  water  apparently  has  no  effect  upon  it,  while  any  sort 
of  leather  produced  with  tannin  and  placed  in  boiling  water  is 
utterly  destroyed  ;  moreover,  chrome  leather  is  of  much  lighter 
weight  than  bark  leather,  and  this  is  a  decided  advantage  for 
almost  all  purposes  for  which  leather  is  used.  On  this  account 
considerable  attention  is  being  given  to  chrome  leather  by  for- 
eign nations  for  military  accoutrements.  It  seems  that  a 
soldier,  fully  equipped,  carries  six  pounds  and  more  of  leather 
about  him,  and  if  this  weight  can  be  decreased  one-half,  his 
efficiency  in  marching  will  be  increased  ;  if  shoes  can  be  made 
of  less  weight  and  more  durable  and  afford  complete  protection 
for  the  feet  from  wet,  such  shoes  will  be  a  wonderful  improve- 
ment over  those  at  present  in  vogue.  Harness  made  from 
chrome-tanned  leather  would  be  much  lighter  in  weight,  would 
not  be  affected  by  the  perspiration  of  the  horse,  nor  deteriorate 
by  exposure  to  the  weather.  Chrome-tanned  machine  belting 
could  be  run  in  wet  and  damp  places  without  fear  of  resulting 
damage  or  injury  to  the  belt.  Experiments  made  in  the  testing 
of  chrome  leathers  indicate:  ist,  that  chrome  leather  excels  in 
strength;  2d,  that  after  reaching  the  stretching  limit  with  a 


"  CHROME,"  OR  MINERAL  TANNAGE. 


321 


corresponding  load,  it  possesses  still  a  considerable  degree  of 
elasticity,  which  is  of  great  value  as  regards  the  adhesion  of 
belts  to  pulleys.  One  of  the  immediate  possibilities  of  the 
future  is  that  chrome-tanned  gloves  will  be  demanded  by  the 
public  in  preference  to  all  others,  simply  because  when  such 
gloves  become  soiled  they  may  be  washed  upon  the  hands  with 
soap  and  water  until  cleansed,  and  when  dried  will  be  as  soft 
and  flexible  as  before  washing. 

CURRYING  CHROME  LEATHER. 

In  the  currying  of  chrome  leather  some  modifications  both  of 
methods  and  materials  are  required  as  compared  with  the  usual 
methods  employed  on  bark  leather.  In  the  first  place  chrome 
leather  does  not  require  nor  will  it  absorb  and  hold  as  much 
oil  and  grease  as  bark  leather:  in  the  second  place,  the  chrome 
leather  should  be  curried  and  stuffed  soon  after  removal  from 
the  tanning  bath,  while  it  is  still  wet  and  before  drying  out, 
because  if  dried  out  immediately  after  tanning  it  is  almost  im- 
possible to  wet  down  the  leather  thoroughly  and  uniformly, 
so  that  it  can  be  properly  stuffed  and  curried.  Probably  the 
most  efficient  means  of  incorporating  oils  and  greases  in  chrome 
leather  is  by  means  of  "fat-liquors,"  so  called.  There  are  vari- 
ous ways  of  preparing  and  using  these  fat-liquors,  according  to 
the  quality  it  is  desired  to  give  to  the  leather.  The  fat-liquor 
in  most  general  use  is  an  emulsion  of  soap  and  oil,  preferably 
a  potash  soft  soap  and  a  fine  quality  of  neats-foot  oil,  used 
warm  and  in  a  dilute  form  and  milled  into  the  leather  by  means 
of  a  pin-mill  drum. 

Other  preparations  are  recommended,  such  as  an  emulsion 
of  degras  and  egg-yolk,  and  also  an  emulsion  of  egg-yolk  and 
olive  oil.  These  fat  liquors  seem  better  adapted  for  lubricating 
the  fibres  and  nourishing  the  leather  than  the  hard  greases  and 
heavy  fish  oils  which  are  used  on  bark  leather.  They  impart 
to  the  chrome  leather  the  necessary  strength  and  flexibility 
without  rendering  it  greasy  and  smeary. 
21 


322 


THE  MANUFACTURE  OF  LEATHER. 


TO  PREPARE  CHROME  TANNED  LEATHERS  POR  DYEING. 

A  patent  has  been  granted  to  E.  Avellis  and  Emil  Koster, 
both  of  Berlin,  Germany,  for  an  improved  method  of  preparing 
chrome-tanned  leather  for  dyeing. 

According  to  the  patentees,  their  invention  has  for  its  object 
the  preparation  of  chrome-dressed  leather,  so  that  it  may  be 
dyed  in  any  desired  shade  or  tint  with  aniline  colors,  and  consists 
in  first  freeing  the  leather  from  acid,  and  subsequent  treatment 
with  materials  containing  tannin,  although,  in  order  to  obtain 
a  clear  tint,  it  will  be  found  expedient  to  re-tan  the  leather  thus 
prepared  with  tartar  emetic,  or  with  preparations  of  the  same. 

The  following  practical  example  will  make  the  process 
clearer : 

In  order  to  free  225  pounds  chrome-tanned  leather  from 
acid,  mix,  in  about  100  quarts  of  water,  7  pounds  whiting 
and  5  pounds  ordinary  salt,  washing  the  leather  in  this  solution 
for  about  a  quarter  of  an  hour,  until  all  trace  of  acid  has  been 
removed,  which  may  be  determined  by  means  of  blue  litmus 
paper.    Next,  rinse  in  water  to  remove  the  chalk. 

Following  the  foregoing  process,  the  leather,  deprived  of 
acid,  is  treated  with  materials  containing  tannin.  When  divi- 
divi  is  used,  2^  pounds  of  the  latter  in  a  solution  of  1  to  2 
deg.  Beaume  to  225  pounds  leather  is  a  very  effective  propor- 
tion, and  a  correspondingly  weakened  solution  may  be  em- 
ployed for  light  tints. 

Although  the  leather  thus  prepared  may  be  dyed  at  once,  it 
is  however,  advisable,  in  order  to  obtain  clearer  tints,  to  first 
re-tan  with  tartar  emetic. 

The  proportions  recommended  for  the  purpose  are :  For 
chrome-tanned  sheep  leather  and  kid,  15  grains  tartar  emetic 
to  3  quarts  liquor  for  each  skin  ;  for  calfskins,  22  to  30  grains  to 
6  quarts  liquor  (according  to  size  of  skin)  ;  cowhides,  100  to 
150  grains  for  10  to  18  quarts.  The  tan  liquors  are  used  at  960 
F.,  the  leather  being  allowed  to  remain  in  the  wheel  or  fulling 
mill  from  5  to  8  minutes;  it  is  then  rinsed  in  fresh  water,  and 
then  dyed  the  desired  color  in  vat  or  drum. 


"  CHROME,"  OR  MINERAL  TANNAGE. 


323 


DYEING  CHROME  LEATHER. 

Chrome  leather  is  easily  dyed,  and  takes  all  shades  of  color 
most  readily.  If  the  neutral  basic  aniline  colors  are  used,  it  is 
necessary  to  mordant  the  leather  with  some  wood-dye,  and  then 
color  to  shade  with  aniline.  For  very  light  shades  a  weak  de- 
coction of  sumac  may  be  used  ;  for  medium  shades  a  fustic 
liquor,  and  for  dark  shades  a  mixture  of  fustic  and  logwood 
may  be  used  as  a  mordant, 

It  is  said  that  the  acid  aniline  colors  dye  directly  without  the 
use  of  a  mordant;  very  recently,  it  is  claimed  that  the  chrome 
leather  may  be  dyed  successfully  with  alizarine  colors. 

In  order  to  fix  alizarine  colors  in  leather,  it  is  necessary  to 
apply  considerable  heat;  for  this  reason  they  are  not  applica- 
ble to  the  ordinary  tanned  goods.  Chrome-tanned  leather  will, 
however,  stand  a  high  temperature  without  the  slightest  dam- 
age, and  for  this  reason  good  results  are  to  be  had  with  aliza- 
rine dyes. 

The  use  of  alizarine  colors  in  powder  form  is  not  generally 
known  to  the  leather  manufacturers,  but  when  it  becomes  so  it 
will  prove  a  great  boon,  as  they  produce  full  bright  colors  that 
are  fast  and  dye  very  evenly. 

Alizarine  dyes  have  a  great  affiinity  for  the  oxide  of  chrome, 
in  fact,  require  a  chrome  mordant,  viz. :  bichromate  of  potash 
and  an  assistant  of  organic  acid  like  lactic  acid  to  produce  the 
oxide  of  chrome.  Inorganic  acids,  like  sulphuric,  muriatic,  or 
even  oxalic,  should  not  be  used,  as  they  have  a  tendency  to 
affect  the  leather,  producing  bad  results. 

Lactic  acid  when  free  from  adulterations,  about  30  degrees 
strength  and  used  with  bichromate  of  potash,  makes  the  best 
"  all-round"  mordant  to  be  used  on  leather,  regardless  whether 
the  same  be  tanned  with  chrome,  vegetable  material  or  alum, 
or  whether  the  dye-stuff  be  wood,  anilines,  or  alizarines,  and  the 
method  of  dyeing  employed  is  that  of  coloring  on  the  table,  in 
the  box,  paddle  or  drum. 

The  application  of  alizarine  to  fibres  other  than  those  of 
vegetable  origin  is  of  comparatively  recent  date,  and  even  ten 


324 


THE  MANUFACTURE  OF  LEATHER. 


years  ago  alizarine  colors  on  wool  were  practically  unknown. 
When,  however,  through  the  breaking  up  of  the  alizarine  syn- 
dicate, alizarine  was  brought  into  the  market  at  a  low  price, 
wool  dyers  began  to  direct  their  attention  to  this  and  allied 
coloring  matter,  with  the  result  that  at  the  present  time  large 
quantities  of  them  are  used  in  the  production  of  fast  shades  on 
loose  wool,  stubbing  and  yarn.  That  their  superiority  over 
other  coloring  matters  is  recognized  by  merchants,  and  prob- 
ably also  by  the  public,  is  revealed  by  the  fact  that  special 
prices  are  sometimes  quoted  for  alizarine-dyed  goods,  as  distinct 
from  such  as  are  dyed  with  other  coloring  matters. 

The  application  of  the  alizarines  in  silk  dyeing  is  of  still 
more  recent  date,  and  although  the  demand  has  hitherto  been 
restricted  to  embroidery,  yarns,  sewing  silks,  and  stripes  for 
trouserings,  the  colors  have  latterly  been  used  for  silk  plush, 
for  seals  and  for  producing  fast  fancy  shades. 

The  usual  method  adopted  in  wool  and  in  silk  dyeing  is  to 
first  mordant  the  material  with  salts  of  chromium,  iron,  alumin- 
ium or  tin  (for  wool,  chrome  is  principally  employed).  After 
washing  off  or  soaping,  the  material  is  immersed  in  the  cold  or 
lukewarm  dye-bath,  and  the  temperature  is  gradually  raised  to 
the  boil  and  kept  at  that  point  until  the  bath  is  exhausted.  The 
actual  formation  of  the  color  lakes  only  begins  at  1940  F.,  and 
is  completed  between  this  temperature  and  the  boiling  point  in 
from  twenty  minutes  to  half  an  hour. 

In  the  case  of  leather  dyeing  with  these  materials  this  pro- 
cedure is,  of  course,  impossible,  except  for  chrome  tanned 
leather,  from  the  fact  that  leather  tanned  with  organic  tannins 
will  become  rotten  if  exposed  to  a  higher  temperature  than 
about  1220  F.  for  any  length  of  time.  The  solution  of  this  dif- 
ficulty has  been  found  by  H.  Koechlin  and  E.  Knecht,  who 
adopt  a  principle  previously  applied  to  wool.  They  first  pad 
the  leather  with  a  solution  of  alizarine  rendered  slightly  alkaline 
with  ammonia,  and  then  develop  in  solutions  of  alumina, 
chromium,  or  iron  salts.  If  the  pieces  are  dried  after  having 
been  padded  in  the  alkaline  color  solution  and  are  then  printed 


"  CHROME,"  OR  MINERAL  TANNAGE. 


325 


with  thickened  acid  or  stannous  chloride,  a  variety  of  white  or 
colored  figures  can  be  obtained  on  colored  grounds.  If,  for  in- 
stance, the  goods,  padded  in  the  ammoniacal  alizarine  solution 
and  dried,  are  printed  with  stannous  chloride  and  then  passed 
through  pyrolignite  of  iron,  an  orange  pattern  is  obtained  on  a 
violet  ground. 

In  the  practical  application  of  this  principle  to  leather  dye- 
ing, the  comparatively  strong,  slightly  atnmoniacal  alizarine 
solution  (or  nitro-alizarine,  a  solution  of  the  monosodium  salt, 
as  the  case  may  be)  is  first  applied  to  the  leather  by  means  of 
a  brush  or  pad,  and  the  color  lake  is  then  formed  by  a  subse- 
quent treatment  in  the  mordant  solution.  Since  it  has  been 
found  that  ordinary  alum  or  nitrate  of  iron  is  liable  to  precip- 
itate a  considerable  amount  of  unchanged  alizarine  in  the 
leather,  it  is  preferable  to  use  these  salts  as  basic  as  possible; 
but  it  is  evident  that  the  process  when  properly  applied,  ensures 
the  production  of  a  large  variety  of  useful  and  fast  alizarine 
shades  on  leather  without  incurring  any  damage  to  the  mate- 
rial, and  this  is  one  more  victory  to  the  credit  of  science  in  the 
art  of  leather  manufacture. 


CHAPTER  XXIII. 


KID  OR  MOROCCO  LEATHERS. 

There  has  been  a  greater  revolution  in  morocco  manufactur- 
ing in  ten  years  than  in  all  the  centuries  of  its  existence.  Skins 
were  formerly  tanned  with  sumac,  gambier  or  alum.  The  new 
agent,  chrome,  was  introduced  in  1884.  This  was  the  most 
important  event  that  ever  occurred  in  the  history  of  the  trade 
— perhaps  in  any  trade.  From  this  material  better  kid  was 
made  than  any  that  had  been  imported.  Its  use  forthwith  re- 
duced the  import  of  foreign  morocco  seventy  per  cent.  From 
being  importers  we  became  large  exporters  of  this  leather. 
The  qualities  of  chrome-tanned  kid,  such  as  imperviousness  to 
water,  firmness  and  softness,  together  with  the  peculiarity  of 
looking  better  in  the  shoe  than  before  it  was  made  up,  caused 
its  universal  adoption.  All  its  merits  were  examined  and  freely 
discussed  in  the  meetings  of  the  Morocco  Manufacturers'  Asso- 
ciation. The  committee  advocated  its  adoption  and  spent  much 
time  in  seeking  to  remedy  some  of  the  early  defects  in  the  tan- 
nage. 

On  January  8th,  1884,  two  patents  were  issued  to  Augustus 
Schultz,  of  New  York  City,  by  the  United  States  Patent  Office, 
for  tawing  hides  and  skins.  These  letters  patent  are  Nos.  291,- 
784  and  291,785,  and  are  later  on  described  in  this  chapter. 
Augustus  Schultz  was,  at  the  time  application  was  made  for 
these  patents,  an  employee  of  the  firm  of  William  Pickhardt  & 
Kuttroff,  New  York,  N.  Y.,  and  at  first  lived  in  Hoboken, 
N.  J.,  but  moved  to  a  house  which  Mr.  Pickhardt  had  pur- 
chased at  No.  135  East  15th  St.,  New  York,  for  the  purpose  of 
fitting  up  for  patents  which  he  possed  for  ventilating  and  heat- 
ing.   His  residence  is  now  near  Manassas,  Virginia.    He  is 

(326) 


KID  OR  MOROCCO  LEATHERS. 


327 


64  years  of  age.  Mr.  Schultz  made  all  of  his  experiments  in 
glass  goblets,  of  large  size,  of  which  he  had  a  half  dozen  or 
more. 

He  knew  of  no  tanner  in  those  days  except  Julius  Kuttner, 
in  the  employ  of  Booth  &  Co.,  of  Gloversville,  N.  Y.  Mr. 
Schultz  asked  Mr.  Kuttner  if  he  knew  of  anything  that  would 
be  of  advantage  to  the  leather  trade,  and  he  replied  that  it 
would  be  desirable  to  find  something  that  would  replace  the  egg 
yolk  which  his  firm  was  using  for  finishing  their  leather.  Mr. 
Schultz  tried  to  find  a  substitute  for  egg  yolk ;  but  this  experi- 
ment was  a  failure,  and  Mr.  Schultz  then  commenced  the  experi- 
ments in  tanning  leather  in  1880,  and  he  continued  these  ex- 
periments until  his  two  patents  were  issued  in  1884. 

The  reason  which  Mr.  Schultz  gives  for  taking  out  two 
patents  is  that  Dr.  Antisell,  who  was  that  time  Examiner  in  the 
U.  S.  Patent  Office,  would  not  allow  hyposulphite  of  soda  to 
come  into  the  patent  with  the  fumes  of  sulphur  and  the  sul- 
phite of  soda. 

Many  tanners  of  kid  leather  use  only  the  process  described 
in  patent  No.  291,784,  which  provides  for  the  use  of  hyposul- 
phite of  soda. 

On  the  15th  day  of  June,  1891,  Augustus  Schultz  sold,  as- 
signed and  transferred  to  Ludwig  Roth  all  his  interest  in  both 
of  said  patents;  and  on  the  30th  day  of  November  1891,  Lud- 
wig Roth  assigned  said  patents  to  Ferdinand  Blumenthal,  Lud- 
wig Roth  and  Julien  S.  Ulman,  constituting  at  that  time  the  firm 
of  F.  Blumenthal  &  Co.,  New  York  City  and  Wilmington,  Del. 

On  December  15th,  1891,  the  firm  of  F.  Blumenthal  &  Co. 
was  dissolved  by  mutual  consent  and  by  the  retirement  of  Lud- 
wig Roth,  and  the  two  patents  were  transferred  to  the  firm  of 
F.  Blumenthal  &  Co.,  composed  of  Ferdinand  Blumenthal  and 
Julien  S.  Ulman.  On  the  1 6th  day  of  June,  1892,  the  firm  of 
F.  Blumenthal  &  Co.  assigned  the  two  said  letters  patent  to 
Marcus  Beebe  and  Robert  H.  Foerderer,  who  in  turn,  on  the 
30th  day  of  August,  1892,  assigned  the  two  said  letters  patent 
to  the  Tannage  Patent  Company,  of  Philadelphia,  Pa.,  who  still 


328 


THE  MANUFACTURE  OF  LEATHER. 


own  them.  The  patents  will  expire  on  the  8th  day  of  January, 
1901. 

The  superior  qualities  of  chrome  tanned  leather  are  its  great 
strength,  its  insolubility  in  water,  its  susceptibility  of  being 
finished  in  various  ways  and  colors,  and  its  excellent  wearing 
qualities.  Leather  made  by  the  chrome  process,  while  being 
exceedingly  soft  and  pliable,  is  less  liable  to  stretch  than  leather 
made  by  other  tannages,  in  other  words,  shoes  made  of  chrome 
leather,  after  being  worn  for  any  length  of  time,  will  retain  their 
size  and  shape  to  a  remarkable  degree.  This  was  not  the  case 
with  leathers  tanned  by  any  of  the  well-known  processes  prac- 
ticed prior  to  the  date  of  the  Schultz  patents.  There  are  reas- 
ons which  make  it  of  great  advantage  to  the  tanner  to  use  the 
chrome  process. 

William  M.  Norris  says:  "The  class  of  goods  which  was 
turned  out  up  to  the  introduction  of  the  Schultz  patents 
ceased  to  be  called  for  by  shoemakers,  and  manufacturers 
were  obliged  to  turn  their  attention  to  the  newer  mineral  tan- 
nages with  a  glazed  finish.  French  kid  was  the  standard  of 
excellence,  and  the  aim  of  experimenters  was  to  reproduce  this 
as  nearly  as  possible.  The  methods  of  tanning  this  leather  in 
France,  as  nearly  as  could  be  ascertained,  were  to  tan  or  taw 
the  skins  with  alum,  salt,  flour  and  egg  yolk,  dry  them  out,  and 
lay  them  away  for  six  months  or  so  before  finishing.  This 
'ageing'  or  'laying  away'  was  essential  in  order  that  the  alum 
should  'set'  and  be  rendered  somewhat  insoluble,  or,  in  other 
words,  that  the  soluble  sulphate  of  alumina  in  the  alum  should 
be  converted  into  the  insoluble  oxide. 

"  This  process  was  altogether  too  slow  for  the  American 
manufacturer,  and  also  the  price  leather  tanned  by  this  process 
commanded  was  not  sufficient  to  recompense  him  for  the  large 
stock  necessarily  carried  and  the  large  capital  required  to  con- 
duct the  business. 

"About  this  time  it  was  discovered  that  gambier  used  in 
connection  with  alum  produced  leather  that  could  be  finished 
at  once,  without  laying  the  stock  away  for  several  months,  and 


KID  OR  MOROCCO  LEATHERS. 


329 


also  that  the  finished  product  was  strong,  handsome,  and  would 
stand  more  wear  than  the  imported  article. 

"This  alum  and  gambier,  or  so-called  'Dongola'  tannage,  is 
entirely  an  American  process,  and  has  been  brought  to  great 
perfection  during  the  last  few  years. 

"While  French  kid  was  only  made  into  high-priced  shoes, 
which  were  naturally  taken  care  of  by  the  purchaser  and  worn 
in  the  house  or  only  out-doors  in  fine  weather  and  on  city 
pavements,  the  American  Dongola  leather,  owing  to  its  lower 
cost,  was  made  into  all  grades  of  shoes,  some  of  which  sold  at 
a  very  low  price  and  which  were  subjected  to  hard  wear  during 
inclement  weather,  often  in  muddy  country  roads  and  on  rough, 
uneven  pavements.  This  soft  kid  leather  is  not  adapted  to 
rough  wear  and  did  not  give  satisfaction  when  subjected  to  it. 
Shoes,  when  soaked,  were  apt  to  dry  out  hard  and  unpliable, 
and  the  grain  was  apt  to  peel  off  when  brought  in  contact  with 
rough  stones  or  subjected  to  the  constant  wear  of  ladies'  dresses. 
Shoe  manufacturers  became  more  and  more  exacting  in  their 
demands.  They  wished  a  gloss  or  finish  that  was  water-proof, 
leather  that  would  stand  a  good  wetting  without  injury,  and 
which  had  a  tougher  grain,  and  so  there  has  been  a  marked 
falling  off  in  the  demand  for  '  Dongola '  leather,  and  the  product 
which  now  seems  to  fill  the  requirements  of  shoe  manufacturers 
is  produced  by  the  so-called  '  acid '  or  '  chrome '  process  of  tan- 
ning. 

"We  are  indebted  for  this  tannage,  not  to  the  numerous 
inventors  and  their  impracticable  processes,  but  to  a  young 
morocco  manufacturer  of  Philadelphia.  This  gentleman  had  in 
his  office  a  few  dozen  skins  of  a  celebrated  French  manufac- 
turer. From  frequent  examinations  of  these  skins  he  became 
convinced  that  there  was  an  indescribable  something  about 
them  that  was  entirely  wanting  in  the  domestic  article.  He 
endeavored  to  produce  stock  like  it,  and  was  understood  by 
his  neighbors  to  be  using  chrome  as  a  tanning  agent.  For 
several  years  his  efforts  resulted  in  few  successes  and  many 
discouragements,  but  finally  he  perfected  all  the  difficult  and 


33Q 


THE  MANUFACTURE  OF  LEATHER. 


minute  details  of  his  process,  and  was  enabled  to  place  a  most 
superior  product  on  the  market.  He  ran  his  factory  to  its 
utmost  capacity,  and  then  moved  to  a  larger  and  more  com- 
modious one,  where,  to  meet  the  demands  of  the  trade,  he 
constantly  increased  his  production  until  it  reached  the  enor- 
mous and  unprecedented  quantity  of  a  thousand  dozen  skins  a 
day. 

"  If  it  had  not  been  for  the  wonderful  success  of  this  Phila- 
delphia manufacturer,  little  would  be  heard  of  chrome  or 
chrome-tanned  leather  to-day. 

"  It  has  long  been  known  that  the  salts  of  chromium  have  a 
strong  affinity  for  gelatine,  and  form  with  it  insoluble  com- 
pounds, and  therefore  have  tanning  power;  but  it  was  not  until 
very  recently  that  these  salts  of  chromium  were  employed  in 
the  manufacture  of  leather  with  success. 

"All  the  salts  of  chromium  may  be  used  for  tanning,  as  well 
as  bichromate  of  potash,  or  magnesia,  chromic  acid,  and 
bichromate  of  ammonia,  aluminium  and  iron. 

"But  so  far  manufacturers  have  generally  confined  their 
attention  to  bichromate  of  potash,  as  this  is  the  most  widely 
known  of  the  chromium  salts. 

"  Potassium  bichromate,  generally  known  as  '  bichromate  '  or 
'  bichrome,'  is  manufactured  in  large  quantities  from  chrome 
iron  ore,  or  chromite,  by  the  action  of  some  oxidizing  agent. 
This  important  mineral  is  found  in  large  quantities  near  Balti- 
more, Md.,  in  Norway  and  the  Shetland  Islands  off  the  coast  of 
Scotland,  as  well  as  in  Asia  Minor,  Siberia  and  Australia. 

"  Bichromate  of  potash  crystallizes  in  anhydrous,  fine  red, 
square  tables,  specific  gravity  2.7,  and  is  of  intensely  metallic 
taste  ;  100  parts  of  water  at  320  F.  dissolve  4.6  parts,  at  6o°  F. 
12.4  parts,  and  at  21 2°  (boiling)  94  parts. 

PREPARING  THE  SKINS. 

When  the  dry  goat-skins  are  removed  from  the  bales,  they 
are  placed  in  the  "soaks,"  which  are  vats  containing  clear  cold 
water,  and  remain  for  from  three  to  five  days,  the  period  of 


KID  OR  MOROCCO  LEATHERS. 


331 


course  depending  upon  the  condition  of  the  skins,  the  hardest 
requiring  a  longer  soaking  than  those  that  are  softer.  Five 
pounds  of  borax  is  added  to  each  1,000  gallons  of  water  in  the 
"soaks;"  the  borax  being  first  dissolved  in  boiling  water  and 
then  thoroughly  stirred  into  the  water  of  the  "soaks."  (See 
Chapter  VI.) 

From  the  "soaks"  the  skins  are  removed  either  with  hooks 
or  tongs,  and  placed,  usually  150  to  200  at  one  time,  in  the 
"pin-mill,"  which  is  a  softening  contrivance,  and  when  suffic- 
iently softened  the  skins  are  next  placed  in  the  "  limes." 

In  many  kid  tanneries  it  is  the  custom  to  break  or  flesh  the 
skins  after  they  come  from  the  "  soaks,"  the  machine  shown  in 
Fig.  95  being  especially  adapted  for  this  purpose. 

Fig.  94  shows  a  view  of  the  lime-vats,  in  a  kid  or  Morocco 
tannery,  and  over  one  of  the  pits  is  shown  a  pile  of  skins  which 
have  been  removed  therefrom  and  placed  upon  planks  to  drain, 
while  in  the  background  is  shown  the  "wash-wheel."  Above 
each  lime-vat  there  is  a  small  blackboard  upon  which  are  marked 
in  chalk  the  number  and  kinds  of  skins  in  each  vat  and  the  date 
on  which  they  were  put  in. 

In  large  Morocco  tanneries  usually  1350  South  American 
goat-skins  are  limed  at  the  same  time,  and  about  600  glove- 
calf,  and  800  glove-sheep  are  placed  in  separate  vats  at  once. 

The  goat-skins  remain  in  the  "limes"  about  14  days,  glove- 
calf  12  days,  and  glove-sheep  8  days.  The  lime  is  mixed  with 
red  arsenic,  as  this  agent  losens  the  fine  hairs  better  than  any 
other.     (See  Chapter  VII.) 

They  then  go  on  to  the  unhairing  machine  shown  in  Fig.  95, 
or  to  the  unhairing  beams,  and  are  unhaired  by  hand,  and  one 
man  will  "  unhair,  flesh,  and  slick"  about  eighty  skins  per 
day. 

The  machine  shown  in  Fig.  95  can  be  used  not  only  for  un- 
hairing, but  for  breaking,  fleshing  and  slating,  and  is  equally 
adapted  to  goat,  sheep,  calf  and  kangaroo  skins.  It  requires 
but  one  operator  to  each  machine,  and  is  economical  in  space 
and  power  required  to  operate  it,  and  is  guaranteed  by  its 


332  THE  MANUFACTURE  OF  LEATHER. 


KID  OR  MOROCCO  LEATHERS.  333 


334 


THE  MANUFACTURE  OF  LEATHER. 


builders,  Vaughn  Machine  Co.,  Peabody,  Mass.,  to  do  better 
work  than  can  be  done  by  hand  or  any  other  machine,  and  at 
the  same  time  quantity  enough  to  suit  anybody,  whether  doing 
a  large  or  small  business. 

The  Vaughn  Machine  Co.  have  thoroughly  remodeled  and 
perfected  this  machine  in  every  detail.  It  is  the  only  machine 
that  will  break  or  flesh  skins  in  the  hair  from  the  soaks  be- 
fore being  limed,  which  is  an  important  thing  to  be  done  on  all 
hard-natured  or  very  fleshy  skins,  as  thereby  the  scale  and  all 
superfluous  flesh  are  removed,  the  skin  thoroughly  spread  out 
and  softened,  and  put  into  the  most  desirable  condition  to  go 
into  the  limes.  For  unhairing  it  is  very  useful  and  profitable, 
as  it  will  do  an  immense  quantity  of  good  work  and  without 
any  damage  whatever.  For  fleshing  it  is  perfection,  doing  the 
work  cleanly,  evenly,  and  without  any  tearing  or  damage 
whatever  ;  the  machine  being  so  completely  under  the  control  of 
the  operator  that  there  is  no  danger  in  fleshing  the  most  delicate 
skin,  while  on  heavy  stock  it  will  cut  down  as  much  as  is 
wanted  ;  therefore,  making  a  great  saving  in  tanning  materials 
and  shaving.  For  slating  nothing  can  equal  it,  as  the  skin  is 
being  worked  both  lengthways  and  sideways  by  the  cylinder  at 
the  same  time,  the  dirt  and  fine  hairs  being  thoroughly  worked 
out  and  with  absolutely  no  danger  of  grain  scratches.  This 
invention  is  a  great  labor  and  time  saver.  It  is  operated  by 
one  man,  and  performs  the  work  of  a  dozen  men. 

It  is  impossible  to  do  any  of  the  above-named  work  in  any 
other  way  nearly  as  well  as  it  can  be  done  with  this  machine. 
The  principle  of  the  machine  is  an  absolute  guarantee  of  this, 
for  the  bed  or  beam  on  which  the  skin  lies  is  carried  over  and 
back  under  the  cylinder,  so  that  it  is  worked  both  ways  at  one 
operation,  and  also  that  the  operator  sees  just  what  is  wanted  to 
be  done  to  each  skin  as  it  goes  through,  and  then  just  how  the 
work  has  been  done  as  it  returns  to  him.  This  insures  perfect 
work  on  each  skin  before  it  leaves  the  machine. 

After  being  unhaired  the  skins  are  placed  in  a  mill  and  thor- 
oughly washed  with  water  and  borax  to  free  them  from  adher- 


KID  OR  MOROCCO  LEATHERS. 


335 


ing  lime  and  dirt,  and  are  next  placed  in  the  slightly-heated 
bate  of  dog  or  pigeon  manure,  in  which  they  remain  overnight. 
(See  Chapter  IX.) 

The  character  of  the  leather  produced  by  any  of  the  chrome 
processes  is  greatly  influenced  by  the  previous  treatment  of 
the  raw  pelt.  It  must  be  remembered  that  all  chrome  tannage 
is  necessarily  light-weighing  and  empty,  since  the  quantity  of 
chrome  oxide  fixed  is  far  smaller  than  in  the  case  of  vegetable 
tannins.  It  is,  therefore,  of  great  importance,  if  plump  leather 
is  required,  that  the  natural  substance  of  the  hide  or  skin 
should  be  spared  as  much  as  possible  in  liming  and  bating  or 
puring.  The  liming  is  best  accomplished  in  '  arsenic  limes  ' 
in  the  case  of  light  goods,  or  with  the  addition  of  y2  pound  or 
more  of  sulphide  of  sodium  per  hide  in  ordinary  limes.  Where 
a  smooth  grain  and  plump  leather  is  important,  chemical  delim- 
ing  is  much  to  be  preferred  to  the  use  of  fermenting  bates 
or  drenches.  Use  a  solution  of  2  per  cent,  boracic  acid  and 
I  per  cent,  of  good  carbolic  acid  in  water,  frequently  after  first 
'pulling  down'  by  paddling  in  warm  water  to  which  about  ^ 
pound  of  sulphuric  acid  and  2  ounces  of  sal-ammoniac  is  added 
per  ioo  pounds  of  wet  pelt.  When  the  goods  come  out,  this 
solution  should  test  slightly  alkaline  to  red  litmus  paper,  and 
if  this  is  not  the  case  sufficient  ammonia  should  be  added  to 
make  it  so,  and  the  goods  paddled  in  it  another  half  hour;  and 
in  future  operations  the  amount  of  acid  must  be  reduced.  The 
boracic  acid  bath  may  be  used  repeatedly ;  goods  will  keep  in 
it  even  for  months  without  change.  If  limey  goods  are  treated 
in  it  without  previous  '  pulling  down,'  it  may  be  made  slightly 
acid  to  litmus  paper  with  hydrochloric  or  sulphuric  acid  each 
time  before  using,  the  strength  being  also  maintained  by  small 
additions  of  boracic  and  carbolic  acids.  In  this  solution  the 
goods  become  quite  free  from  lime,  but  remain  pretty  plump 
and  full,  and  if  tanned  in  chrome  liquor  which  is  not  too  strong 
at  first,  and  without  too  violent  motion,  remain  perfectly  smooth 
in  the  grain. 

Upon  removal  from  the  bate  the  skins  are  "slated,"  which  is 


336 


tup:  manufacture  of  leather. 


the  removal  of  the  fine  hair  remaining  upon  the  skins  after  the 
unhairing  operation.  The  machine  shown  in  Fig.  95  can  be 
used  or  the  hand  method  may  be  employed ;  the  "  slater"  is  a 
tool  closely  resembling  a  "  slicker,"  but  the  edge  of  the 
"slater"  is  ground  sharp. 

The  skins  are  now  passed  into  the  bran  drench,  which  is 
composed  of  bran  and  water,  slightly  heated,  and  in  this  they 
remain  usually  over  night  and  are  then  finally  washed  with 
borax  water. 

TAWING. 

If  the  skins  are  to  be  tawed  according  to  the  Schultz  patent, 
they  are  immersed  after  the  final  washing  with  borax  and  water 
in  a  bath  containing  about  five  per  cent,  of  the  weight  of  the 
skins  of  bichromate  of  potash,  and  about  two  per  cent,  of  hydro- 
chloric acid,  since  this  amount  of  acid  is  sufficient  to  enable  the 
skins  to  absorb  the  liquor;  the  skins  are  placed  in  a  reel,  with 
sufficient  water  to  enable  them  to  freely  rotate  by  means  of  the 
action  of  the  paddle-wheel;  the  skins  are  left  in  this  solution 
until  this  yellow  liquor  has  thoroughly  penetrated  the  skins, 
and  have  assumed  an  even  yellow  color  all  the  way  through, 
which  is  determined  by  cutting  pieces  from  the  thickest  part 
of  the  skin,  and  when  this  even  yellow  color  shows  evenly 
through  the  skins,  they  are  ready  to  receive  the  second  bath. 
After  removing  the  skins  from  the  first  bath,  the  skins  are 
allowed  to  drain,  or,  in  order  to  expedite  matters,  the  surplus 
liquor  is  sometimes  pressed  out  before  putting  them  into  the 
second  bath.  A  bath  is  then  prepared  of  about  ten  per  cent, 
of  hyposulphite  of  soda  of  the  weight  of  the  skins,  and  about 
two  and  a  half  per  cent,  of  hydrochloric  acid,  and  sufficient 
water  to  enable  the  skins  to  float  by  the  same  mechanical 
means  as  described  in  the  first  bath  ;  the  skins  are  placed  in 
the  second  bath,  and  allowed  to  remain  therein  until  they 
assume  a  whitish,  bluish  or  greenish  color  all  the  way  through. 
This  is  also  determined  by  cutting  pieces  from  the  thickest  part 
of  the  skin ;   and  when  the  yellow  color  has  entirely  disap- 


KID  OR  MOROCCO  LEATHERS. 


337 


peared,  the  skins  are  done  ;  this  completes  the  tanning.  Some 
of  the  stock  is  put  on  the  market  with  no  further  treatment 
other  than  mechanical.  Some  of  the  stock  is  finished  in  various 
ways,  in  black  and  fancy  colors  and  dull  and  glazed  surfaces, 
and  any  treatment  subsequent  to  that  of  tanning  is  based 
entirely  upon  the  result  obtained  for  the  purpose  for  which  the 
leather  is  to  be  sold. 

Skins  are  frequently  tanned  in  baths  constituted  in  different 
proportions  of  the  materials  as  given.  The  proportions  are 
varied  according  to  the  character  of  the  skins  and  the  product 
desired.  Sometimes  as  high  as  eight  per  cent,  of  the  weight  of 
the  skins  of  bichromate  of  potash  and  five  per  cent,  of  hydro- 
chloric acid,  and  as  low  as  three  per  cent,  of  bichromate  of 
potash  and  one  per  cent,  of  hydrochloric  acid.  There  is  no 
necessary  hard  and  fast  rule  that  must  be  followed. 

Neither  is  there  any  hard  and  fast  rule  that  must  be  followed 
in  regard  to  the  amount  of  water  used,  or  in  other  words  in  re- 
gard to  the  degree  of  concentration  of  the  baths.  On  this 
point  the  greatest  latitude  is  permissible.  As  a  matter  of  fact, 
tanners  vary  this  according  to  the  apparatus  which  may  be 
most  convenient  for  them  to  use;  when  skins  are  treated  in  the 
first  bath  in  a  drum  the  liquor  is  very  much  more  concentrated 
than  when  treated  in  a  reel.  In  treating  skins  in  a  drum,  the 
skins  are  placed  in  a  drum  together  with  the  tanning  liquor; 
the  drum  is  securely  closed  and  then  caused  to  revolve,  and  the 
action  caused  thereby  causes  the  skins  to  be  raised  in  the  drum 
and  then  fall  back,  which  has  a  pounding  action  upon  the 
skins  and  causes  any  liquors  that  are  present  to  be  rapidly 
absorbed.  In  a  drum,  a  comparatively  small  amount  of  liquor 
is  used,  because,  if  a  large  amount  of  liquor  is  used  the 
mechanical  action  of  raising  the  skins  and  allowing  them  to  fall 
back  would  not  take  place,  and  the  skins  and  the  liquor  would 
remain  at  the  lowest  point,  while  the  drum  would  revolve  with- 
out causing  agitation  of  the  mechanical  action  that  would 
facilitate  the  absorption  of  the  liquor  by  the  skins.  The  reel 
is  a  vat  made  in  a  semi-circular  shape,  in  the  centre  of  the  top 
22 


338 


THE  MANUFACTURE  OF  LEATHER. 


of  which  is  mounted  an  ordinary  paddle-wheel.  In  order  to 
procure  the  mechanical  action  desired,  it  is  necessary  to  use  an 
amount  of  liquor  in  the  reel  such  that  the  blades  of  the  paddle 
extend  a  sufficient  depth  into  the  liquor.  The  action  desired 
is  to  cause  the  skins  to  be  constantly  rotated  or  agitated  in  the 
liquor,  in  order  that  every  part  and  portion  of  the  skins  may  be 
brought  in  contact  with  the  liquors,  and  that  the  skins  should 
not  remain  in  a  folded  position  where  the  penetration  might 
not  be  even  and  uniform.  For  the  reasons  given,  it  is  custom- 
ary to  use  more  liquor  and  the  baths  are  less  concentrated 
when  treating  skins  in  a  reel  than  when  treating  them  in  a 
drum.  The  only  difference  in  the  two  methods  is  that  in  the 
case  of  tanning  in  the  drum  penetration  is  accomplished 
quicker  and  in  less  time  than  when  tanned  in  a  reel.  The  re- 
sult in  the  product,  however,  is  exactly  the  same. 

The  reel  and  drum  described  above  are  well  known  forms  of 
apparatus  used  by  tanners  for  tanning  hides  and  skins.  The 
hydrochloric  acid  above  mentioned  is  the  same  as  muriatic 
acid,  and  ranges  from  twenty  to  twenty-two  degrees  and  is 
added  to  the  bichromate  of  potash  after  it  has  been  thoroughly 
dissolved,  which  is  done  by  heating  the  water  and  the  above 
specified  weight  of  muriatic  acid  is  then  poured  into  the  vat. 
The  second  bath  is  prepared  after  dissolving  the  hyposulphite, 
the  muriatic  acid  is  added,  usually  two  to  two  and  a  half  pounds 
to  one  hundred  pounds  of  skins,  and  after  stirring  this  thor- 
oughly the  skins  are  placed  in  this  bath  ;  the  acid  being  of  the 
same  degree  as  in  the  first  bath.  The  hyposulphite  of  soda 
after  dissolving  and  being  placed  in  this  bath  can  hardly  be 
noticed  ;  as  soon,  however,  as  the  muriatic  acid  is  added  the 
color  changes  to  a  bluish  green  and  creates  sulphurous  acid 
which  can  be  detected  at  once  by  the  smell,  and  it  is  as  much 
as  one  can  do  to  stand  it.  This  bath  changes  the  color  of  the 
skins  from  a  yellow  to  a  bluish  white. 

It  is  not  known  what  the  chemical  reactions  are  which  take 
place  when  the  skins  which  have  been  treated  in  the  first  bath 
(patent  No.  291,785)  are  subjected  to  the  action  of  the  second 
bath. 


KID  OR  MOROCCO  LEATHERS. 


339 


It  is  evident  from  the  change  in  color  that  a  change  takes 
place  in  the  condition  of  the  chromium  of  the  first  bath  ;  it  is 
evident  that  what  the  chemist  calls  a  reduction  takes  place. 
Some  oxygen  is  taken  away  from  the  chromium  compound, 
and  the  yellow  compound  of  chromium  containing  much  oxygen 
is  changed  to  a  green  compound  which  contains  less.  This  is 
about  as  much  as  is  definitely  known  with  regard  to  the  chemi- 
cal reaction. 

The  bichromate  of  potash  has  no  effect  upon  the  skins  what- 
ever, and  the  only  object  in  soaking  the  skins  in  the  bichromate 
of  potash  is  to  have  the  bichromate  of  potash  in  the  proper 
place  at  the  proper  time  when  the  actual  process  of  tanning  is 
to  begin.  The  tanning  always  takes  place  in  the  second  bath. 
Here  certain  chemical  changes  take  place  between  the  material 
contained  in  the  second  bath  and  the  bichromate  of  potash  and 
the  skin.  There  is  no  special  significance  in  the  word  "  bath." 
"  Bath  "  is  nothing  but  a  solution,  and  all  you  can  say  is  that 
previous  to  the  date  of  these  patents,  skins  had  been  dipped  into 
a  solution  of  something  else,  such  as  chloride  of  barium.  In 
this  case  these  two  substances  acting  upon  each  other,  produced 
a  yellow  powder,  consisting  of  chromate  of  baryta,  which  fills 
the  pores  of  the  skin. 

The  essential  discovery  made  by  Schultz  was  that  an  im- 
proved leather  resulted  from  the  action  of  the  agents  which 
liberate  sulphurous  acid  upon  metallic  salts,  such  as  bichromate 
of  potash  in  the  pores  of  the  skin.  He  further  discovered  that 
still  better  results  could  be  obtained  by  selecting  hyposulphite 
of  soda  as  the  agent  to  be  used  in  connection  with  the  bichro- 
mate of  potash. 

It  cannot  be  determined  exactly  what  the  chemical  reactions 
are  which  take  place  in  the  skins,  when  a  bath  containing 
sulphurous  acid  acts  upon  the  bichromate  of  potash,  and  when 
a  bath  containing  hyposulphurous  acid  acts  upon  the  bichro- 
mate of  potash.  Sulphurous  acid  is  one  thing;  hyposulphur- 
ous acid  is  another.  It  is  true  that  hyposulphurous  acid  under- 
goes decomposition  and  produces  sulphurous  acid,  but  that  is 


34Q 


THE  MANUFACTURE  OF  LEATHER. 


not  all  it  produces.  It  produces  finely  divided  sulphur,  and 
it  is  very  probable  that  the  action  of  the  hyposulphite  of  soda 
involves  more  than  the  action  of  sulphurous  acid  alone.  At 
all  events,  it  is  said  to  give  better  results  in  practice,  so  there 
must  be  some  advantage  in  it  even  though  it  may  not  be 
known  what  chemical  actions  occurs. 

It  is  known  that  hyposulphurous  acid  will  often  accomplish 
results  in  chemical  reactions  which  sulphurous  acid  alone  will 
not  accomplish. 

The  operations  involved  in  carrying  out  the  process  set  forth 
in  patent  No.  291,784  are  the  same  as  in  patent  No.  291,785 
until  we  come  to  the  preparation  of  the  second  bath  described 
in  the  last  mentioned  patent.  In  this  case  the  skins  coming 
from  the  first  bath  are  treated  in  a  second  bath,  which  con- 
sists of  a  solution  capable  of  evolving  sulphurous  acid,  such, 
for  instance,  as  a  solution  of  sulphite  or  bisulphite  of  soda,  to- 
gether with  some  acid  stronger  than  sulphurous  acid,  such  as 
hydrochloric  acid.  The  skins  are  allowed  to  remain  in  this  bath 
until  the  change  in  color  induced  by  the  liberated  sulphurous 
acid,  (and  which  may  be  to  a  whitish  or  blush  or  greenish  color 
according  to  the  thickness  of  the  skins,  and  consequently  the 
time  required  to  complete  the  action,)  has  penetrated  through 
them.  They  may  then  be  removed  and  finished  after  the 
ordinary  manner. 

Some  people  have  regarded  the  two  patents  above  men- 
tioned issued  to  Augustus  Schultz  as  deficient  or  even  partially 
misleading  in  their  descriptions.  This  is  not  so,  as  the  direc- 
tions given  are  sufficiently  full,  clear  and  exact  to  enable  any 
person  skilled  in  the  art  to  which  the  patents  relate,  to  success- 
fully carry  out  the  processes,  and  result  in  the  production  of  a 
useful  product.  Any  person  skilled  in  the  art,  upon  taking  up 
these  patents  with  a  desire  to  put  them  in  practical  operation, 
would  have  no  difficulty  in  understanding  either  the  object  at 
which  they  aim  or  the  means  set  forth  for  the  attainment  of 
that  object,  or  of  the  materials  which  may  be  used,  or  of  the 
manner  in  which  they  may  be  employed. 


KID  OR  MOROCCO  LEATHERS. 


341 


In  tanning  goat-skins  for  kid  leathers  the  skins  remain  in 
the  first  bath  for  about  one-half  day,  and  sometimes  longer,  if 
upon  examination  they  were  found  to  be  not  thoroughly  tanned  ; 
this  examination  being  made  by  cutting  the  neck  of  the  skin 
and  seeing  that  no  animal  or  raw  material  is  left. 

The  skins  are  left  in  the  second  bath  until  no  show  of  bichro- 
mate or  yellow  is  apparent.  This  process,  by  some  tanners,  is 
applied  to  the  skins  in  the  afternoon,  and  they  are  allowed  to 
remain  in  the  liquor  of  the  second  bath  over  night.  Sometimes 
the  skins  are  needed  as  quickly  as  possible,  stock  that  has  been 
actually  sold  or  is  needed  for  order  is  required,  and  instead  of 
leaving  the  skin  in  the  second  bath  over  night,  they  are  washed 
and  rushed  right  along.  The  time  that  the  skins  remain  in  this 
bath,  under  such  circumstances,  is  only  for  a  few  hours,  the 
time  depending  of  course  upon  the  thickness  of  the  skins  under 
treatment. 

It  has  been  demonstrated  in  practice  that  the  use  of  sulphuric 
acid  in  the  first  bath  and  muriatic  acid  in  the  second  bath 
would  not  prevent  the  carrying  out  of  the  Schultz  process  and 
making,  by  the  aid  of  it,  leather. 

This  was  tested  practically  by  Professor  Samuel  P.  Sadtler 
on  January  4,  1894,  at  the  tannery  of  Burk  Bros.,  in  Philadel- 
phia, Pa.  He  took  a  goat  skin  from  the  regular  stock  of  pre- 
pared skins  the  skin  weighing  about  twelve  ounces.  It  was  put 
in  a  bath  of  one  hundred  and  twelve  fluid  ounces  of  water,  three- 
quarters  of  an  ounce  of  bichromate  of  potash  in  crystals,  and 
one-half  an  ounce  of  strong  sulphuric  acid.  The  skin  was 
entered  at  1 1  :  50  a.  m.  at  a  temperature  of  87  degrees  F.  for 
the  bath.  It  was  taken  out  at  3  :  25  p.  m.  after  testing  it  for 
penetration  in  the  usual  manner.  It  was  then  struck  out  or 
freed  from  excess  of  moisture,  and  at  3  :  45  p.  m.  it  was  entered 
into  a  bath  of  hyposulphite  of  soda,  one  and  three-quarter 
ounces,  and  one-half  an  ounce  of  muriatic  acid  of  210  Baume, 
dissolved  in  the  same  amount  of  water  as  that  of  the  first  bath. 
It  was  taken  out  after  testing  it  for  completion  of  the  reaction  at 
5  :  15  p.  m.,  and  was  struck  out.  It  was  then  put  in  freshwater 
over  night.    The  result  was  good  merchantable  leather. 


342 


THE  MANUFACTURE  OF  LEATHER. 


The  sulphuric  acid  of  commerce  usually  contains  a  percent- 
age of  hydrochloric  acid  sufficient  for  the  work. 

In  patent  No.  291,  785  Mr.  Schultz  says:  "An  aqueous 
solution  of  sulphurous  acid  may  be  used."  This  undoubtedly 
means  that  in  place  of  the  two  chemicals  which  are  first  pre- 
scribed as  to  be  taken  for  the  evolution  of  sulphurous  acid,  an 
aqueous  solution  of  sulphurous  acid  could  be  taken  of  such  a 
character  as  to  accomplish  substantially  the  results  intended  by 
the  use  of  the  mixed  sulphite  of  soda  and  muriatic  acid. 

Strong  acid  solutions  would  undoubtedly  have  an  injurious 
effect  upon  the  hide,  of  course  that  injurious  effect  would  con- 
tinue into  the  leather  produced.  The  skins  would  be  swollen 
very  rapidly  in  a  relatively  strong  acid  bath,  and  in  that  swollen 
condition  the  penetration  of  the  bichromate  salt,  if  the  first  bath 
be  referred  to,  or  the  penetration  of  the  chemicals  of  the  second 
bath,  equally  would  be  hindered  to  a  very  considerable  degree ; 
and  at  the  same  time,  in  addition  to  this  swelling  or  "  plump- 
ing," as  it  is  termed,  the  acid  is  steadily  disintegrating  the 
fibre,  acting  upon  the  connective  tissue  of  the  hide,  as  it  is 
termed. 

The  plumping  is  a  surface  indication  of  the  effect  of  the  acid, 
and  it  undoubtedly  preceded  the  other  effect,  that  is,  opening 
up  or  partially  dissolving  the  connective  tissue  ;  and  while  some 
plumping  always  takes  place  at  stages  of  the  tanning  proceeses, 
excessive  plumping  is  to  be  avoided,  and  in  this  case  it  is 
especially  to  be  avoided,  for  the  reason  that  it  would  prevent 
the  penetration  of  the  salts  which  are  to  be  the  effective  tanning 
agents  in  the  Schultz  process. 

When  a  skin  is  introduced  into  an  acidulated  bath  and  the 
skin  plumps,  that  bath  contains  too  much  acid.  This  may  be 
noticed  in  the  difference  between  the  effect  of  neutral  bichromate 
of  potash  solution  and  acidified  bichromate  of  potash  solution. 
In  the  neutral  bichromate  of  potash  solution  the  skin  retains 
for  a  long  time  the  soft,  slimy  feeling  of  the  hide,  and  in  the 
acidified  bichromate  of  potash  solution  even  with  very  small 
amounts  of  acid,  there  is  a  distinct  surface  roughening  which 


KID  OR  MOROCCO  LEATHERS. 


343 


might  be  termed  an  incipient  plumping,  but  which  has  no 
notable  effect  in  the  way  of  injury. 

The  tan  vat  used  in  the  two-bath  method  of  chrome  tannage 
is  7  feet  long,  5  feet  6  inches  wide,  and  5  feet  deep.  Semi- 
circular to  within  1  foot  of  top,  where  it  is  plumb  up.  Over  this 
vat  there  is  a  revolving  wheel  5  feet  6  inches  long  and  3  feet  in 
diameter.  This  wheel  has  7  wings  in  it;  they  are  2  inches 
thick  and  9  inches  deep. 

There  are  at  least  two  of  these  vats  in  each  morocco  factory 
where  the  chrome  process  is  used,  that  is,  the  two-bath  process. 

SPECIFICATION  OF  SCHULTZ'S  FIRST  PATENT  (NO.  291,  784). 

This  invention,  says  Mr.  Schultz,  relates  to  a  new  process  for 
tanning  hides  or  skins,  said  process  consisting  in  subjecting  said 
hides  or  skins  to  the  action  of  compounds  of  metallic  salts — 
such  as  bichromate  of  potash — and  then  treating  the  same  with 
hyposulphite  of  soda,  by  which  term  is  understood  that  salt 
which  is  more  recently  sometimes  called  "  thiosulphate  of 
soda  "  (Na2S203). 

In  carrying  out  my  process,  I  unhair  the  raw  hides  and  pre- 
pare them  in  the  same  manner  in  which  they  are  made 
"ready"  for  tanning.  If  the  hides  have  not  been  pickled,  I 
subject  them  to  the  action  of  a  solution  of  bichromate  of  potash 
in  the  presence  of  an  acid,  such  as  hydrochloric  acid,  or,  if  the 
hides  have  been  pickled,  they  may  be  treated  in  a  solution  of 
bichromate  of  potash  in  water  without  the  addition  of  an  acid. 
In  this  solution  the  hides  are  left  for  a  shorter  or  longer  time, 
according  to  their  thickness  and  to  the  strength  of  the  solution 
employed.  A  skiver  or  the  face  of  a  sheepskin  can  be  done  in 
a  strong  solution,  as  above  described,  in  about  fifteen  minutes, 
while  a  full  skin  "roan"  would  require  in  the  same  solution 
about  one  hour.  I  call  the  solution  "weak"  if  it  contains  5 
per  cent,  or  less  of  the  weight  of  skins  of  bichromate  of  potash, 
and  I  call  the  solution  "  strong  "  if  it  contains  more  than  5  per 
cent  of  bichromate  of  potash.  It  is  not  material,  however,  how 
strong  the  solution  is.    The  skins  are  completed  if  small  pieces 


344 


THE  MANUFACTURE  OF  LEATHER. 


cut  from  the  thickest  part  of  said  skin  show  that  the  solution 
has  entirely  penetrated.  The  skins  are  then  ready  to  be  taken 
out,  and  after  the  adhering  liquor  has  run  off,  the  skins  are  in- 
troduced into  the  second  solution,  which  consists  of  hyposul- 
phite of  soda  dissolved  in  water,  and  adding  an  acid  such  as 
hydrochloric  acid.  The  solution  may  be  strong  or  weak  of 
hyposulphite,  and  the  quantity  of  acid  used  at  first  may  be  less 
than  requisite  to  split  up  the  entire  quantity  of  hyposulphite, 
and  more  acid  may  be  added  if  the  skins  show  that  more  is  re- 
quired, which  is  indicated  by  the  color  of  the  skins.  When 
they  are  done  they  show  a  whitish,  bluish  or  greenish  color, 
according  to  the  time  they  are  kept  in  the  hyposulphite  solu- 
tion. A  skiver  which  has  first  been  exposed  to  the  action  of 
the  bichromate  for  fifteen  minutes  will  be  ready  by  remaining 
in  the  hyposulphite  solution  about  twenty  minutes.  For  thicker 
skins  a  proportionately  longer  time  is  required.  For  some  skins, 
such  as  calf  or  steer's  skins,  it  is  desirable  that  the  same,  after 
having  been  drawn  from  the  second  or  hyposulphite  solution, 
shall  be  returned  to  the  bichromate  solution,  which  imparts 
to  them  a  brownish  color,  and  leaves  them  in  a  favorable 
condition  to  be  colored  black.  The  coloring  can  be  done 
after  the  skins  leave  the  hyposulphite  solution,  and  after 
they  have  been  exposed  the  second  time  to  the  bichromate 
solution.  The  leather  coming  from  the  hyposulphite  solution 
is  especially  adapted  for  light  or  dark  colors,  and  by  proper 
dyeing  methods  better  and  brighter  colors  can  be  produced 
than  on  leather  done  by  tanning.  After  the  leather  is  treated 
in  the  manner  above  indicated,  it  may  be  colored,  soaped  and 
greased  in  the  usual  way.  Leather  can  also  be  made  by  re- 
versing the  operation  and  first  soaking  the  hides  in  a  solution 
of  hyposulphite  of  soda,  and  then  exposing  them  to  the  action 
of  the  bichromate  solution.  By  using  the  solutions  indicated 
at  a  heat  of  8o°  Fah.,  the  process  will  be  done  in  a  shorter  time 
than  if  the  solutions  are  used  cold.  By  my  process  the  gelatine 
contained  in  the  hides  is  rendered  insoluble  by  means  not  in- 
jurious to  the  leather.    If  leather  made  by  tannin  is  put  in  a 


KID  OR  MOROCCO  LEATHERS.  345 

strong  soda  solution,  the  tannin  is  extracted  and  a  dark-brown 
liquor  formed.  If  leather  made  by  my  process  is  put  in  a 
strong  soda  solution,  the  liquor  obtained  shows  only  a  little 
milky  color.  Leather  made  by  my  process  is  very  strong,  soft, 
elastic,  and  my  process  is  applicable  to  hides  or  skins  of  every 
description. 

SPECIFICATION  OF  SCHULTZ'S  SECOND  PATENT   (NO.  291,785). 

This  invention,  says  Mr.  Schultz,  relates  to  the  new  process 
for  treating  hides  or  skins,  said  process  consisting  in  subjecting 
said  hides  or  skins  to  the  action  of  a  bath  prepared  from  a 
metallic  salt — such  as  bichromate  of  potash — and  of  then  treat- 
ing the  same  with  a  bath  containing  sulphurous  acid. 

In  carrying  out  my  process  I  unhair  the  raw  hides  and  pre- 
pare them  in  the  same  manner  in  which  they  are  made  ready 
for  tanning.  If  the  hides  have  not  been  pickled,  I  subject 
them  to  the  action  of  a  bath  of  bichromate  of  potash  in  an  acid, 
such  as  hydrochloric  acid  ;  or,  if  the  hides  have  been  pickled, 
they  may  be  treated  in  a  solution  of  bichromate  of  potash  in 
water  without  the  addition  of  an  acid.  In  this  solution  the 
hides  are  left  for  a  longer  or  shorter  time,  according  to  their 
thickness  and  to  the  strength  of  the  solution  employed.  A 
skiver  or  the  face  of  a  sheepskin  can  be  done  in  a  strong  solu- 
tion, as  above  described,  in  about  fifteen  minutes,  while  a  full 
skin  "roan"  would  require  in  the  same  solution  about  one 
hour.  I  call  the  solution  weak  if  it  contains  5  per  cent,  or  less 
of  the  weight  of  the  skins  of  bichromate  of  potash,  and  I  call 
the  solution  strong  if  it  contains  more  than  5  per  cent,  of 
bichromate  of  potash.  The  skins  are  done  if  small  pieces  cut 
from  the  thickest  part  thereof  show  that  the  solutions  have 
entirely  penetrated.  The  skins  are  then  ready  to  be  taken  out 
of  the  solution,  and,  after  the  adhering  liquor  has  run  off,  the 
skins  are  introduced  into  the  second  bath,  which  consists,  by 
preference,  of  sulphite  of  soda  dissolved  in  water,  to  which  an 
acid — such  as  hydrochloric  acid — should  be  added,  in  order  to 
set  free  the  sulphurous  acid.    The  hydrochloric  acid  or  its 


346  THE  MANUFACTURE  OF  LEATHER. 

substitute  may  be  added  to  the  bath  in  a  free  state  or  through 
the  medium  of  skins  previously  pickled,  such  skins  being  im- 
pregnated with  the  proper  acid.  The  solution  may  be  strong 
or  weak  of  sulphite,  and  the  quantity  of  acid  used  may  be  in- 
creased if  the  skins  show  that  more  is  required,  which  is 
indicated  by  the  color  of  the  skins.  When  the  skins  are  done 
they  show  a  whitish,  bluish,  or  greenish  color,  according  to  the 
time  they  are  kept  in  the  sulphite  bath.  A  skiver  which  first 
has  been  exposed  to  the  action  of  the  bichromate  bath  for 
fifteen  minutes  will  be  ready  by  remaining  in  the  sulphite  bath 
about  twenty  minutes.  For  thicker  skins  a  proportionately 
longer  time  is  required. 

For  some  skins — such  as  calf  or  steer  skins — it  is  desirable 
that  the  same,  after  having  been  withdrawn  from  the  second  or 
sulphite  bath,  shall  be  returned  to  the  bichromate  bath,  which 
imparts  to  them  a  brownish  color  and  leaves  them  in  a  favor- 
able condition  to  be  colored  black.  The  leather  coming  from 
the  sulphite  bath  is  especially  adapted  for  light  and  also  for 
dark  colors,  and  by  proper  dyeing  methods  better  and  brighter 
colors  can  be  produced  than  on  leather  done  by  tannin.  After 
the  leather  is  done  in  the  manner  above  described,  it  may  be 
colored,  soaped  and  greased  in  the  usual  way. 

Leather  can  also  be  made  by  reversing  the  operation  and  first 
soaking  the  hides  in  a  sulphite  bath,  and  then  exposing  them 
to  the  action  of  the  bichromate  bath.  By  using  the  baths  de- 
scribed at  a  heat  of  about  8o°  Fahrenheit,  the  process  will  be 
done  in  a  shorter  time  than  if  the  baths  are  used  cold. 

Tawed  leather  made  by  my  process  is  very  strong,  soft  and 
elastic,  and  my  process  is  applicable  to  hides  or  skins  of  every 
description. 

Instead  of  using  sulphite  of  soda,  I  can  use  other  sulphites 
or  bisulphites  in  presence  of  an  acid  or  an  aqueous  solution  of 
sulphurous  acid. 

Concerning  these  patents,  William  M.  Norris  says: 

1.  Hides  or  skins  are  prepared  for  tanning  in  the  usual  way. 

2.  They  are  then  subjected  to  the  action  of  a  solution  of 
bichromate  of  potash  in  the  presence  of  an  acid. 


KID  OR  MOROCCO  LEATHERS. 


347 


3.  The  hides  or  skins  are  introduced  into  a  second  solution, 
which  consists  of  hyposulphite  of  soda  dissolved  in  water,  to 
which  an  acid  is  added  to  liberate  the  sulphurous  acid. 

4.  They  are  then  finished  in  the  usual  way. 

Some  years  ago  Mr.  Schultz  sent  a  circular  to  the  trade  in 
which  he  gives  further  information,  and  enters  more  into  details 
about  his  process,  as  follows : 

Pickled  roans  or  similar-treated  skins,  rinse  in  700  F.  warm 
water,  or  leave  in  water  over  night. 

First  Bath. — For  every  100  pounds  of  skins,  dissolve  4  pounds 
bichromate  of  potash  in  about  six  to  eight  times  the  quantity 
of  boiling  water,  then  add  2  pounds  muriatic  acid,  stir  well,  and 
leave  stand  about  half  an  hour,  then  add  this  liquor  to  the  vat 
containing  water  sufficient  to  cover  the  skins,  which  must  be 
suspended  in  it.  The  suspended  skins  should  hang  sufficiently 
far  apart  to  allow  the  liquor  an  uniform  penetration,  which 
cannot  be  accomplished  if  the  skins  touch  and  press  each  other. 
Leave  the  skins  in  this  liquor  until  the  yellow  color  of  the 
chrome  has  thoroughly  penetrated,  which  can  be  perceived  by 
cutting  off  a  small  piece  from  the  thickest  part  of  an  average 
skin,  and  if  the  cut-off  part  shows  an  even  yellow  color,  then 
the  skins  are  done;  take  out;  let  drain,  press  out  adhering 
liquor  (perhaps  a  centrifugal  machine  will  do  it),  and  the  skins 
are  now  ready  for  the  second  bath. 

Second  Bath. — For  every  100  pounds  skins  dissolve  in  the 
vat  containing  the  water  in  which  the  skins  have  to  be  sus- 
pended and  sufficient  to  cover  the  skins,  10  pounds  hyposul- 
phite of  soda;  stir  well  until  all  is  dissolved,  then  add  2^ 
pounds  muriatic  acid,  stir  again,  and  enter  at  once  the  skins 
which  were  done  in  the  first  bath,  and  keep  the  skins  suspended 
in  this  liquor  until  the  yellow  color  has  disappeared  and  the 
skins  have  become  whitish  all  through,  which  can  be  perceived 
by  cutting  off  a  small  piece  of  the  thickest  part  of  the  skin. 
Now  take  out,  let  drain,  press  out  surplus  liquor,  and  the 
skin  has  become  leather  and  may  now  be  finished  in  the  ordi- 
nary way.    I  found  it  advantageous  for  suppleing  the  leather 


348 


THE  MANUFACTURE  OF  LEATHER. 


to  put  in  a  solution  of  about  3  or  4  per  cent,  soap,  leave  it  in 
several  hours  or  over  night,  or  rub  a  soft  soap  on  both  sides 
and  let  it  lie  sometime.  Steer  skins  for  sole  leather,  or  any- 
other  leather  which  is  suppled  by  grease,  should  receive  such 
grease  soon  after  coming  from  second  bath  and  before  the 
leather  has  commenced  to  dry. 

The  advantages  of  making  leather  by  this  process  are :  It  is 
adapted  to  all  kinds  of  hides  or  skins,  furs  or  chamois.  The 
leather  by  this  process  is  much  denser  —  tougher  —  therefore 
more  durable  than  leather  made  in  the  ordinary  way,  by  tan- 
bark,  sumac,  gambier,  etc.  The  leather  by  this  process  can  be 
boiled  in  water  without  impairing  its  quality  ;  it  remains  leather, 
while  all  other  leather  made  by  tannin  will  be  totally  spoiled — 
destroyed  by  boiling.  The  thinner  kinds,  as  sheep,  will  not 
shrink  by  boiling.  The  boiling  test  is  a  characteristic  mark  of 
this  process.  Because  belts  have  sometimes  to  be  exposed  to 
heat,  which  is  hurtful  to  tanned  leather,  beltings  made  from 
leather  by  this  process  promise  more  durability.  The  dyer  is 
enabled  to  make  brighter  colors  ;  on  account  of  the  color  of  this 
leather  being  whitish,  it  taking  color  with  great  ease.  Sole 
leather  now  made  at  the  depots  of  tanbark  can  be  made  by  this 
process  near  any  city.  The  freight  to  and  from  present  tan- 
neries is  almost  entirely  saved.  The  saving  of  time  and  of 
interest  on  capital,  is  large,  because  the  tanning  of  hides  and 
skins  by  this  process,  as  steer-skin  for  sole  leather,  takes  only 
forty-eight  to  ninety-six  hours  according  to  thickness.  Sheep- 
skin skivers  may  be  done  in  about  three  hours,  sheep-skin  roans 
in  three  to  six  hours,  sheep-skin  fleshes,  for  chamois  or  gloves, 
in  three  hours.  The  materials  used  for  this  process  are  of  low 
cost. 

The  bichromate,  or  first  bath,  if  not  exhausted,  may  remain 
for  the  next  lot,  only  adding  thereto  a  suitable  quantity  of 
bichromate  and  acid.  For  the  hyposulphite  bath  it  may  ap- 
pear well  to  use  at  first  only  half  of  the  given  quantities,  and 
after  the  liquid  becomes  clear,  and  the  sulphurous  acid  smell 
is  faint,  and  the  skin  showing  to  need  more,  then  more  hypo- 


KID  OR  MOROCCO  LEATHERS. 


349 


sulphite  and  acid  may  be  added  by  pouring  this  additional 
liquor  in  at  one  side  of  the  vat  without  lifting  the  skins,  only 
motioning  the  skins  in  vat.  The  preparing  of  the  skins,  as 
liming,  sweating,  unhairing,  plumping,  before  they  enter  the 
tan  liquors,  must  be  done  also  for  this  process,  and  this  pro- 
cess is  distinguishable  chiefly  by  the  kind  of  liquor  used  against 
the  ordinary  tanbark  process. 

Before  considering  the  chemistry  of  this  process,  the  char- 
acteristics of  the  articles  used,  their  properties  and  reactions 
upon  one  another,  mention  should  be  made  of  Mr.  William 
Zahn,  one  of  the  pioneer  manufacturers  of  chrome  tanned 
leather  in  this  country.  Mr.  Zahn  secured  a  patent  covering 
his  process  on  June  28,  1888. 

SPECIFICATION  OF  THE  ZAHN  PATENT. 

My  invention,  says  Mr.  Zahn,  relates  to  an  improved  process 
of  tanning  skins  for  making  kid  leather,  and  the  process  con- 
sists, first,  in  preparing  the  skins  for  tanning  by  treatment  with 
sulphide  of  sodium  or  arsenic  and  unhairing  the  same,  then 
treating  it  with  dog  manure  and  a  solution  of  salt  and  water. 
After  this  preparatory  treatment  the  skins  are  exposed  to  the 
action  of  three  different  solutions,  the  first  solution  consisting 
of  bichromate  of  potassium,  salt  and  muriatic  acid  ;  the  second 
solution  of  hyposulphite  of  soda  and  sulphuric  acid,  and  the 
third  solution  of  a  mixture  of  neat's  foot  oil  saponified  by 
caustic  soda  and  extract  of  quercitron-bark,  or  other  tannin- 
containing  extract. 

For  preparing  the  skins  and  producing  a  strong  and  soft  kid 
leather  in  a  much  shorter  time  than  heretofore,  the  skins  are 
first  treated  with  sulphide  of  sodium  for  about  three  or  four 
days — for  seven  to  eight  days  when  arsenic  is  used.  The  skins 
are  then  unhaired,  scraped  and  placed  in  dog  manure  for  some 
time.  The  skins  are  then  cleaned  of  the  dog  manure  and 
placed  in  a  solution  of  five  pounds  of  common  salt  and  one 
hundred  pounds  of  water,  in  which  they  are  allowed  to  remain 
for  about  one-half  hour.    They  ar-e  then   removed  and  ex- 


350 


THE  MANUFACTURE  OF  LEATHER. 


posed  to  the  first  bath,  which  consists,  for  every  one  hundred 
pounds  of  skins,  of  a  solution  of  five  pounds  of  bichromate  of 
potassium,  two  pounds  of  salt,  and  two  and  one-half  pounds  of 
muriatic  acid  in  five  gallons  of  water.  The  skins  are  placed 
with  this  solution  in  a  tub  and  rotated  by  stirrers  in  the  same 
for  about  thirty  minutes,  so  as  to  be  thoroughly  impregnated 
by  the  solution.  The  skins  are  then  allowed  to  remain  in  the 
solution  for  about  three  hours,  after  which  they  are  again 
rotated  for  about  thirty  minutes  with  the  same.  Thinner  skins 
have  to  be  exposed  to  the  action  of  the  solution  for  a  less 
length  of  time  than  thicker  skins,  which  have  to  remain  for  a 
greater  length  of  time  in  the  solution,  so  as  to  be  thoroughly 
impregnated  by  the  same.  The  skins  are  then  transferred  to 
the  second  bath,  which  consists,  for  every  hundred  pounds  of 
skins,  of  eight  pounds  of  hyposulphite  of  soda  (Na2S203)  and 
one  and  one-half  pounds  of  sulphuric  acid  of  6  deg.  Baume, 
dissolved  in  ten  gallons  of  water.  The  skins  are  placed  with 
the  solution  in  the  tub  and  agitated  in  the  same  for  about 
half  an  hour.  After  an  intermission  of  half  an  hour  they  are 
again  agitated  for  half  an  hour,  and  then  allowed  to  remain  in 
the  same  from  two  to  ten  hours,  according  to  the  thickness 
of  the  skins.  They  are  then  washed  and  placed  in  the  third 
bath,  by  which  the  leather  is  made  soft  and  strong,  and  which 
consists,  for  every  one  hundred  pounds  of  skins,  of  a  mixture 
of  saponified  neat's-foot  oil  and  two  ounces  of  caustic  soda, 
which  are  dissolved  in  one  gallon  of  water  and  heated  by  steam 
until  the  neat's-foot  oil  is  properly  saponified.  Then  an  ex- 
tract of  five  pounds  of  quercitron  bark  in  five  gallons  of  water, 
or  any  other  suitable  solution  containing  tannic  acid  is  added. 
The  skins  are  placed  with  this  solution  in  the  so-called  "  pin- 
wheel,"  the  last  solution  softening  the  skins  and  imparting  the 
final  tanning  action  to  the  same.  The  skins  are  exposed  to  the 
tannic  acid  solution  for  about  half  an  hour,  after  which  the 
leather  is  removed  and  dyed  in  the  usual  manner. 

For  light  colors,  the  dye  is  given  to  the  leather  while  it  is  in 
the  pin-wheel,  it  being  finally  washed  off  and  allowed  to  dry, 


KID  OR  MOROCCO  LEATHERS. 


351 


while  for  dyeing  black  it  is  best  to  remove  the  leather  to  the 
working  bench  and  spread  the  color  over  the  same.  A  coating 
of  oil  is  then  given  to  the  leather  on  the  grain  side,  after  which 
it  is  dried  at  a  temperature  of  from  700  to  80°  Fahrenheit.  If 
a  gloss  is  to  be  imparted  to  the  leather,  a  coating  of  some  veg- 
etable oil,  preferably  linseed  oil,  is  finally  given,  which  renders 
the  leather  water-proof,  soft  and  durable. 

By  my  improved  method  of  tanning  skins,  the  same  can  be 
changed  into  leather  in  from  fourteen  to  sixteen  days,  the  pro- 
cess producing  kid  leather  of  superior  quality. 

For  the  chrome  bath  Schultz  directs  for  each  100  pounds  of 
skins  4  pounds  bichromate  of  potash,  2  pounds  muriatic  acid; 
and  for  the  hypo  bath  for  each  100  pounds  of  skins  10  pounds 
hyposulphite  of  soda  and  2^  pounds  muriatic  acid;  while 
Zahn  prescribes  for  the  chrome  bath,  for  every  100  pounds  of 
skins  5  pounds  bichromate  of  potash,  2  pounds  of  salt,  2^ 
pounds  muriatic  acid;  and  for  the  hypo  bath,  for  each  100 
pounds  of  skins  8  pounds  hyposulphite  of  soda  and  I  ^  pounds 
sulphuric  acid  of  6°  Baume.  The  strength  of  the  sulphuric  acid 
mentioned  is  probably  a  mistake.  No  doubt  6o°  or  65 0  Baume 
was  what  the  inventor  meant. 

In  order  to  express  the  composition  of  substances,  and  in 
representing  the  results  of  chemical  action,  more  conveniently 
than  can  be  done  by  writing  the  names  of  the  elementary  con- 
stituents at  full  length,  chemists  use  a  kind  of  short-hand,  or 
symbolic  language,  which  is  very  simple  when  once  explained. 
Instead  of  writing  the  whole  name,  the  first  letter,  or  if  the 
names  of  two  or  more  elements  begin  with  the  same  letter,  the 
first  two  letters  of  the  name  are  employed  to  designate  the  ele- 
ment;  sometimes  using  the  Latin  or  Greek  name.  Thus,  in- 
stead of  hydrogen,  we  write  H  ;  for  oxygen,  O ;  for  nitrogen, 
N,  etc.  For  carbon  we  write  C;  for  chlorine,  CI;  for  chro- 
mium, Cr,  etc.  For  iron  we  write  Fe,  from  Latin  ferrum;  for 
copper,  Cu,  from  cuprum  ;  for  potassium,  K,  from  kalium  ;  for 
sodium,  Na,  from  natrium.  These  letters,  however,  signify 
more  than  this  ;  they  stand  not  only  for  the  elements  in  ques- 


352 


THE  MANUFACTURE  OF  LEATHER. 


tion,  but  they  all  have  certain  numbers  belonging  to  them, 
which  indicate  the  proportions  by  weight  in  which  the  several 
elements  are  found  to  combine  with  each  other.  Thus,  H  does 
not  signify  any  weight  of  hydrogen,  but  always  I  part  by  weight. 
O  signifies  always  16  parts  by  weight  of  oxygen,  because  it  has 
been  found  that  the  density  or  weight  of  a  given  volume  of 
oxygen  compared  with  that  of  the  same  volume  of  hydrogen  is 
1 6 — hydrogen,  as  the  lightest  body  known,  being  taken  as  the 
unit;  so  all  the  other  elements  have  in  the  same  way  been 
compared  with  hydrogen  and  certain  numbers  given  them, 
which  is  their  weight.  CI  (chlorine)  is  35.5;  K  (potassium) 
is  39;  Na  (sodium)  is  23  ;  S  (sulphur)  is  32.  Hence,  it  is 
evident  that  we  may  express  by  symbols  not  only  the  qualita- 
tive but  also  the  quantitative  composition  of  chemical  sub- 
stances.   Thus,  water  consists  of 

Hydrogen   2  X  1  or  H2. 

Oxygen  1 6        or  O. 

The  symbol  for  water  is,  therefore,  H20.  The  juxtaposition 
of  the  letters  signifies  that  the  elements  are  combined  together 
in  the  proportions  by  weight  indicated  by  the  respective  letters. 
The  figure  2  placed  below  the  letter  H  shows  the  combining 
weight  of  hydrogen  (i)  is  to  be  taken  twice.  The  sum  of  the 
combining  weights,  in  this  case  18,  is  the  combining  weight  of 
the  compound,  water. 

In  preparing  the  chrome  bath  each  of  the  inventors  uses  a 
certain  quantity  of  bichromate  of  potash  and  one-half  this 
quantity  of  muriatic  acid.  The  reactions  which  occur  here  are 
K2Cr207  (bichromate  of  potash) -f  2HCI  (muriatic  acid)— Cr206 
(chromic  acid)+2KCl  (chloride  of  potash)-r  H,0  (water). 
That  is,  the  muriatic  acid  breaks  up  the  bichromate  and  forms 
chromic  acid,  chloride  of  potash  and  water.  But  why  should 
one-half  the  quantity  of  acid  be  used  ? 

To  find  the  combining  weight  of  bichromate  of  potash : 


KID  OR  MOROCCO  LEATHERS.  353 

The  weight  of  K  is  39,  that  of  K,2  is   78 

The  weight  of  Cr  is  52.5,  that  of  Cr._,  is  105 

The  weight  of  O  is  16,  that  of  O,  is  112 

K.2Cr207  (Bichromate  of  potash)  is  295 

The  weight  of  H  is   1 

The  weight  of  CI  is  35.5 

HC1  (muriatic  acid)  is   36.5 


2HCI  is  73,  so  when  295  parts  of  bichromate  of  potash  are 
taken,  73  parts  of  muriatic  acid  are  required,  or  when  1  pound 
of  bichromate  of  potash  is  taken  0.248  pound  muriatic  acid  is 
required — say  ^  of  a  pound.  But  this  is  on  the  supposition 
that  the  articles  are  of  full  strength  and  chemically  pure,  which 
is  generally  far  from  being  the  case.  Muriatic  acid  is  a  colorless 
transparent  gas ;  it  dissolves  in  water  very  readily,  and  in  this 
combination  is  known  in  the  trade.  The  commercial  article  is  a 
yellowish  liquid,  the  color  being  due  to  the  presence  of  impur 
ities.  A  strong  solution  of  the  gas,  which  stands  about  25  de- 
grees Baume,  contains  40  per  cent,  of  muriatic  acid.  The 
ordinary  commercial  article  stands  from  18  degrees  to  20  de- 
grees Baume,  and  contains  about  30  per  cent,  of  muriatic  acid. 
Now,  granting  that  the  bichromate  of  potash  of  trade  is  pure 
and  of  full  strength,  1  pound  would  require  about  ^  of  a 
pound  of  muriatic  acid  to  liberate  all  the  chromic  acid. 

In  the  hypo  bath  Schultz  takes  IO  pounds  hyposulphite  of 
soda  and  2]/^  pounds  muriatic  acid,  while  Zahn  uses  8  pounds 
hyposulphite  of  soda  and  lyi  pounds  sulphuric  acid.  It  is  im- 
material which  acid  is  used,  as  the  function  of  the  acid  is  to 
break  up  the  hyposulphite  of  soda  and  liberate  the  sulphurous 
acid,  which  is  what  is  required  to  set  the  chromic  acid  in  the 
skins. 

The  formula  is,  where  muriatic  acid  is  used  : 

Na2S203+5H.20  (hyposulphite  of  soda)  +2HCI  (muriatic  acid) 
— S0.2  (sulphurous  acid)+S  ( sulphur) +  2NaCl  (chloride  of 
sodium  )  +H20  (water). 

Thus  we  have  sulphurous  acid,  which  is  given  off  as  a  gas 
23 


354 


THE  MANUFACTURE  OF  LEATHER. 


with  its  peculiar,  characteristic,  pungent  odor,  sulphur  which 
separates  out  as  a  yellowish  white  powder,  chloride  of  sodium 
which  remains  in  solution. 

To  determine  the  proper  amount  of  acid  to  use  in  connection 
with  the  hypo : 


The  weight  of  Na  is  23,  that  of  Na2  is   46 

The  weight  of  S  is  32,  that  of  S2  is   64 

The  weight  of  O  is  16,  that  of  03  is   48 

The  weight  of  H20  is  18,  that  of  5H20  is   90 

Na2S2035H20  (hyposulphite  of  soda)  is  248 


We  have  previously  determined  that  the  combining  weight 
of  muriatic  acid  is  36.5.  So  where  248  parts  of  hyposulphite 
of  soda  are  taken,  73  parts  of  muriatic  acid  are  required,  or  to 
1  pound  of  hyposulphite  of  soda  0.3  pounds  muriatic  acid ; 
but  as  muriatic  acid  is  only  30  per  cent,  pure,  1  pound.  So 
where  1  pound  of  bichromate  of  potash  is  taken,  ^  of  a  pound 
of  muriatic  acid  should  be  used,  and  to  each  pound  of  hypo- 
sulphite of  soda  I  pound  muriatic  acid. 

In  the  same  way  we  can  determine  the  proper  relation 
between  the  bichromate  and  the  hypo : 

Cr2Oe  (chromic  acid)  +  3S02  (sulphurous  acid)  -f  3H20  (water)  =  Cr2Os 
(chromic  oxide)  -)-  3H2S04  (sulphuric  acid). 


The  weight  of  Cr  is  52.5,  that  of  Cr2  is  105 

The  weight  of  O  is  16,  that  of  Ofi  is   96 

Cr206  (chromic  acid)  is  201 

The  weight  of  S  is  32   32 

The  weight  of  O  is  16,  that  of  02   32 

S02  (sulphurous  acid)  is   64 

3S02  (sulphurous  acid)  is  192 


Therefore  20 t  parts  of  chromic  acid  require  192  parts  sul- 
phurous acid. 

Now,  glancing  at  first  series  of  formulas  it  will  be  seen  that 
295  parts  of  bichromate  are  necessary  to  produce  201  parts 
chromic  acid ;  and  from  second  series  formulas  it  will  be  seen 
that  248  parts  of  hyposulphite  of  soda  are  required  to  produce 


KID  OR  MOROCCO  LEATHERS. 


355 


64  parts  sulphurous  acid.  But  as  192  parts  of  sulphurous  acid 
are  necessary,  it  will  require  744  of  hyposulphite  of  soda.  So 
when  we  take  295  parts  of  bichromate  of  potash  we  require 
744  parts  of  hyposulphite  of  soda,  or  when  1  pound  of 
bichromate  is  used,  2.53  pounds  of  hyposulphite  of  soda  are  re- 
quired— say  2^  pounds. 

In  this  manner  we  arrive  at  the  theoretical  quantities  of  the 
different  ingredients  used,  but  it  has  been  found  expedient  to 
vary  the  relative  quantities  in  practical  use. 

Both  inventors  first  saturate  the  skins  with  chromic  acid  and 
then  reduce  this  chromic  acid  to  chromic  oxide  by  means  of 
sulphurous  acid. 

When  a  solution  of  bichromate  is  acted  upon  by  muriatic 
acid,  chromic  acid  and  chloride  of  potash  are  formed.  This 
chloride  of  potash,  although  it  does  not  assist  at  all  in  the  tan- 
ning process,  at  the  same  time  exerts  no  injurious  influence. 
Skins,  when  saturated  with  chromic  acid,  are  in  a  most  sensi- 
tive condition,  and  should  be  handled  most  carefully.  The 
length  of  time  they  are  exposed  to  the  air,  the  state  of  the  at- 
mosphere, and  particularly  sunlight,  all  have  a  marked  effect 
upon  them. 

When  hyposulphite  of  soda  is  acted  upon  by  muriatic  acid, 
we  have  sulphurous  acid,  sulphur,  chloride  of  sodium  ;  and  the 
sulphurous  acid,  when  acting  upon  the  skins,  breaks  up,  form- 
ing sulphuric  acid.  So  the  stock  is  necessarily  subjected  to 
the  action  of  all  the  above  named  articles,  which  certainly  is 
not  at  all  beneficial,  quite  the  reverse. 

Sulphurous  acid  itself  is  a  difficult  reducing  agent  to  prop- 
erly control.  It  adheres  most  tenaciously  to  the  skins,  and 
efforts  made  to  remove  it  are  not  always  successful.  To  this 
are  due  many  of  the  troubles  which  beset  the  manufacturer  who 
undertakes  to  work  this  process,  because  when  leather  is 
finished  without  having  previously  thoroughly  removed  every 
trace  of  sulphurous  acid,  it  will  harden,  crack,  show  grease 
spots,  and  be  in  every  way  most  unsatisfactory.  In  fact,  to 
proceed  to  manufacture  leather  according  to  the  directions 


356 


THE  MANUFACTURE  OF  LEATHER. 


which  these  inventors  give  us,  would  result  in  a  not  very  satis- 
factory or  salable  product.  After  the  skins  have  been  tanned 
in  the  liquors  above  described,  they  should  be  washed  in  warm 
water,  then  in  ^  to  i  per  cent,  borax  solution,  and  finally  in 
water.  All  chrome  goods  must  be  fat  liquored  (see  Chapter 
XV.)  and  dyed  before  they  become  dry,  or  soaked  in  some  kind 
of  a  solution  to  prevent  complete  drying  out,  as  one  contain- 
ing 5  per  cent,  salt  and  5  per  cent,  glucose. 

PUTTING-OUT  MACHINE. 

The  work  of  "putting  out"  goat  and  sheep-skins  in  the  pro- 
cess of  manufacturing  Morocco  leather  was  commonly  done  by 
hand  ;  but  machines  have  been  invented  for  this  purpose  that 
are  steadily  coming  into  use. 

The  object  is  to  press  out  the  water  and  tanning  liquor,  and 
to  scrape  off  the  small  pieces  of  flesh  or  other  imperfections 
that  adhere  to  the  flesh  side  of  the  skin,  and  to  render  the  grain 
side  smooth  and  otherwise  to  improve  its  appearance. 

Fig.  96  shows  a  perspective  view  of  Vaughn's  machine  for 
"putting  out"  and  also  striking  out  goat,  sheep,  calf  and  kan- 
garoo skins.  It  is  built  by  the  Vaughn  Machine  Co.,  Peabody, 
Mass. 

This  machine  is  so  well  and  extensively  known  and  used 
throughout  this  country  and  Europe  that  a  description  is  hardly 
necessary.  It  is  the  only  machine  that  will  do  the  work,  and 
its  excellence  is  proved  by  the  fact  that  it  now  has  nearly  sup- 
planted all  hand  work  in  this  branch  of  the  business.  Its  con- 
struction consisting  of  two  parallel  cylinders,  revolving  in  op- 
posite directions,  and  a  vertical  table  on  which  the  skin  is  placed 
passing  up  through  them,  is  sufficient  to  convince  anybody  that 
it  cannot  help  doing  the  work  much  better  than  it  can  be  done 
by  hand,  as  the  whole  skin  is  worked  at  once  and  from  the 
back  to  the  belly,  taking  out  all  bag  and  stretch  thoroughly, 
leaving  the  skin  fine,  dry,  even,  smooth,  and  in  perfect  shape ; 
in  fact,  perfectly  put  out  in  every  particular. 

The  manufacturers  guarantee  that  this  machine  will  put  out, 


KID  OR  MOROCCO  LEATHERS. 


357 


both  first  and  second  way,  all  kinds  of  chrome-tanned  stock, 
Russia  calf  and  all  fancy-colored  skins,  India  tanned  goat  and 
sheep-skins  in  any  finish,  sheep-skins  either  bark,  sumac,  or 
Dongola  tanned,  glazed,  mat  or  dull  kids  of  any  tannage,  kan- 


358 


THE  MANUFACTURE  OF  LEATHER. 


garoo  skins,  and  in  fact  anything  that  is  now  made  by  manu- 
facturers of  morocco  and  light  leathers  of  all  kinds ;  that  it  will 
entirely  take  the  place  of  all  hand  work  for  this  purpose  in  the 
factory. 

The  same  machine  will  either  strike  out  or  put  out,  or  both. 

They  claim  a  decided  gain  in  measurement  over  hand  work, 
besides  the  great  saving  of  labor.  Very  little  space  or  power 
is  required  to  operate  it.  Each  machine  is  fitted  specially 
with  the  proper  cylinders  for  doing  any  particular  kind  of  work 
required,  and  guaranteed  to  give  perfect  satisfaction.  The 
machine  is  very  efficient,  and  it  leaves  the  skins  dry,  even 
smooth,  and  in  a  most  desirable  condition. 

Necks,  butts,  and  shanks  are  also  put  out  by  it  in  a  better 
manner  than  it  is  possible  to  perform  the  work  by  hand. 

Under  the  present  system  of  chrome  tannage  every  step  of 
the  finishing  process  is  accomplished  by  a  different  person, 
each  man  having  his  own  specialty.  A  seasoning  mixture  is 
applied  to  the  surface  after  tanning  and  before  coloring. 

Fig.  97  shows  a  form  of  seasoning  machine  which  is  largely 
used  for  all  kinds  of  glazed  kid.  It  is  the  invention  of  Shute 
and  Faulkner,  Lynn,  Mass.,  practical  morocco  manufacturers, 
doing  a  large  glazed  kid  business  and  whose  seasoning  is  done 
wholly  with  this  machine,  as  is  also  that  of  nearly  all  the  other 
Lynn  manufacturers,  who  will  attest  to  the  efficiency  and  prac- 
ticability of  this  machine  for  the  above  named  work. 

The  machine  is  built  by  the  Vaughn  Machine  Co.,  Peabody, 
Mass. 

In  construction  it  consists  of  a  wheel,  carrying  two  sets 
of  flexible  pads,  arranged  on  opposite  sides  of  the  wheel, 
beneath  the  wheel  two  circular  forms  attached  to  levers,  treadle 
rods  and  treadles  to  raise  and  lower  them,  each  form  to  serve  as 
a  bed  for  the  set  of  pads  which  pass  directly  over  it,  and  a 
metallic  apron  or  spreader  above  the  wheel  to  distribute  the 
seasoning  evenly  on  one  set  of  pads,  together  with  the  table  to 
support  the  skin,  and  shelf  to  hold  the  seasoning  tank. 

The  mode  of  operating  the  machine  is,  to  pass  a  skin  under 


KID  OR  MOROCCO  LEATHERS. 


359 


the  wheel,  between  the  pads  and  circular  bed,  to  start  the  sea- 
soning running,  usually  from  a  slow  to  a  very  fast  drop  is  suffi- 
cient, according  to  the  quantity  of  seasoning  required  to  be 
spread  on  the  skin.    By  placing  the  foot  on  the  treadle  it 


Fic.  97. 


SEASONING  MACHINE.     (FAULKNER  PATENTS.) 


brings  the  skin  up  to  and  in  contact  with  the  revolving  pads, 
then  by  drawing  the  skin  from  the  left  to  the  right,  the  left 
hand  or  spreading  set  of  pads  passing  over  the  skin  first 
spreads  the  seasoning,  and  the  right  hand  set,  which  remains 
comparatively  dry,  following  after  the  wet  ones,  rubs  the  sea- 
soning thoroughly  into  the  skin. 


360 


THE  MANUFACTURE  OF  LEATHER. 


The  quantity  of  work  that  a  machine  will  do  depends  so 
much  on  the  condition  of  the  skins  and  the  seasoning,  that  no 
definite  numbers  can  be  given,  but  it  has  been  found  in  almost 
every  instance  to  do  from  two  to  three  times  as  many  as  can  be 
done  by  hand.  The  quality  of  work  is  always  as  good,  and  in 
many  cases  better  than  previously  done  by  hand,  owing  to  the 
immense  amount  of  rubbing  that  the  machine  does,  which  can 
be  better  understood  by  a  comparison  of  the  number  of  strokes 
it  makes  on  the  skin,  with  the  number  made  by  hand  in  the 
same  time. 

Allowing  a  man  to  make  a  stroke  a  second,  which  would  be 
very  fast  work,  the  machine  carrying  twenty  pads  runs  at 
eighty  revolutions,  making  1,600  strokes  per  minute  against  60 
strokes  by  hand. 

The  machine  can  be  easily  adjusted  to  the  pressure  re- 
quired, also  to  make  it  season  heavy  either  on  the  sides  or 
middle  of  the  skin. 

Owing  to  its  simplicity  of  operation,  and  good  results  in  both 
quality  and  quantity  of  work  done,  it  is  fast  being  adopted  by 
all  leading  manufacturers  of  the  country,  and  cannot  help  being 
universally  used  by  all  manufacturers  of  glazed  kid  in  the  near 
future. 

For  seasoning  use  ^  blood,  y£  flaxseed  water  strained,  and 
a  few  drops  of  sulphuric  acid ;  this  makes  a  splendid  strong 
seasoning.  In  some  factories  they  use  1  pint  of  milk  and  1  pint 
of  water. 

The  skins  are  then  thrown  into  the  coloring  drum  and 
thrashed  about  in  the  coloring  liquid  for  an  hour.  The  plaiter 
next  takes  it  in  hand,  folds  it  down  the  back,  face  out,  and  runs 
lightly  over  it  with  a  tool  known  as  a  "  slicker,"  causing  the 
inner  sides  to  closely  adhere.  Then  he  rubs  in  a  scour  with  a 
hard  brush,  and  the  skin  is  turned  over  to  the  boxman.  This 
latter  dips  it  into  a  box  filled  with  a  black  liquid,  and  turns  and 
shifts  it  for  some  fifteen  minutes.  Then  it  is  run  through  a 
"striking-out"  machine  shown  in  Fig.  96,  which  removes  all 
superfluous  moisture.    The  skins  are  then  packed  in  saw  dust, 


KID  OR  MOROCCO  LEATHERS. 


36r 


staked  and  shaved  down  on  the  emery  wheel  and  then  the  skin 
is  glazed  by  machines,  seasoned  a  second  time  with  milk  and 
water  and  reglazed,  after  which  it  is  hung  in  a  steam-heated 
room  to  dry,  and  this,  save  for  light  oiling,  completes  the  pro- 
cess. 

In  Figs.  98  to  105  we  show  the  plans  of  the  kid  factory 
of  F.  Blumenthal  &  Co.,  Wilmington,  Del.  This  is  one  of  the 
largest  establishments  of  its  kind  in  the  United  States  using  the 
chrome  process  and  is  at  the  present  time  being  greatly  en- 
larged. 


Fig. 


Fk;.  99. 


J 


-  33ft  -  -~ 


fEsI555o55oDr"  00 


.?« Er«»  Pure  Tubs 


DDD  DD 

Wash  Reels 


■p  □□□□□□□  'jiJlJ 

J  L- 1       pure  tubs 


—  MURE    rUBS  STAKING  MACMIN13  •-, 

□  1  app    □□  n  □  d  o  □  d  rjj. 


QSteaming 

PUBf  □□□ 


FIHST  FLOOH 


167  ft 


The  plans  show  the  number  of  machines  in  each  room,  but 
do  not  show  the  fifth  and  sixth  floors,  which  are  mainly  de- 
voted to  steam  drying.  There  are,  however,  above  the  perch- 
ing room  on  the  fourth  floor,  two  large  logwood  tanks,  and  in 


362 


THE  MANUFACTURE  OF  LEATHER. 


the  opposite  wing,  above  the  general  storeroom,  a  sawdust 
room. 

The  capacity  of  the  plant  is  1,500  dozens  of  skins  daily.  The 
machinery  is  of  the  latest  and  best.  There  are  33  Vaughn 
machines,  186  Bowers  glazing  machines,  70  Hysore  glazers, 
20  color  boxes,  12  pleating  tables,  6  blue  backing  and  fat 
liquoring  drums,  14  tanning  drums,  44  hypo,  reels,  28  Weber 


Fig.  100. 


Fig.  ioi. 


QDDQDDQDOD 

Vaughn Strihin&Out  Machincs 

DT,PW  □"[]"[] 

-   =J  ODDDDODD  ' 

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stakers,  50  knee  stakers  and  12  Slocomb  perching  machines. 
These  perching  machines  take  the  place  of  hand  work,  as 
they  are  far  more  efficient  and  speedy.  About  1,000  hands 
are  usually  employed ;  200  girls  do  the  seasoning,  glazing  and 
measuring.    The  product  is  glazed  kid,  black  and  in  colors. 

This  firm  was  among  the  first  to  adopt  the  chrome  process. 
They  bought  the  Schultz  patent,  and  sold  it  to  the  Patent  Tan- 


KID  OR  MOROCCO  LEATHERS. 
Fig.  102.  Fig.  103. 


TOlMMfNG 

Room 

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Slocomb  Perching  machines 

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Sawyer  Q 
Measuring 


363 


Towebs  Glazing 

llllllllllllllllllllllllllllll 
iiimiiiijimiiiiiiiiiiiiiii 

 Machines  


T«I^D  FLOOH. 


Fig.  104. 


,  PfB((HING0  FRAMES. 


STOBE«~D  DRUIj 
ROOM  *ok 

Tanning  Dept 


Perching 


FQUHTH  PI_OOT» 


Fig.  105. 


OnuG 
Room 


seasoning 
Room 


Seasoning  Room 


nage  Company,  of  Philadelphia,  Pa.,  reserving  to  themselves 
the  right  to  use  it.  They  import  all  the  skins  they  tan,  and 
have  the  advantage  of  a  close  European  selection. 


364 


THE  MANUFACTURE  OF  LEATHER. 


INDIA  TANNED  GOAT. 

The  finishing  of  India  tanned  goat  skins  is  an  important 
branch  of  manufacture  in  Peabody,  Mass.,  and  in  some  other 
parts  of  the  country. 

In  good  times  several  thousand  dozens  of  these  skins  are 
finished  in  Peabody  every  week.  The  amount  of  goatskins 
imported  from  India  greatly  outnumbers  that  of  the  sheep,  and 
they  fill  a  place  in  the  manufacture  of  shoes  entirely  distinct 
and  independent.  All  the  Morocco  leather  that  is  produced  in 
the  United  States  from  skins  in  the  hair  is  made  by  the  chrome 
or  oxide  process,  which  renders  it  soft,  springy  and  elastic,  and 
entirely  unfit  for  pebble  grain  work.  Here  is  where  the  India 
goat  comes  in.  Being  tanned  in  the  slow,  natural  way,  it  has  a 
firmness  and  body  entirely  suitable  for  graining  and  pebbling. 
It  also  makes  a  cheap  kid  a  pretty  fair  color,  and  a  dull 
Dongola  for  men's  shoes.  All  these  skins  undergo  cleansing 
and  retanning  processes,  and  while  furnishing  leather  for 
ordinary  grades  of  shoes,  do  not  conflict  with  the  chrome 
leather,  except  on  a  few  lines. 

There  is  some  Morocco  leather  still  produced  in  the  United 
States  by  the  old  method  of  sumac  tanning. 

SUMAC  TANNED  SKINS. 

If  the  skins  have  been  tanned  with  sumac  they  are  next 
"struck  out"  on  mahogany  tables,  which  are  so  shaped  as  to 
slant  from  the  workman  at  an  angle  of  about  450. 

A  steel  "slicker"  is  used  for  this  operation,  and  an  average 
workman  will  "strike  out"  about  200  skins  in  ten  hours. 

The  object  of  this  operation  is  to  increase  the  size  of  the 
skins,  remove  the  adhering  "  fleshings,"  tanning  liquors,  and 
water,  and  render  the  skins  smooth  and  even,  and  this  is  ac- 
complished in  many  tanneries  by  the  employment  of  machinery. 

The  skins  after  being  "  struck  out  "  are  hung  up  in  the  dry- 
ing lofts  and  dried  by  the  atmosphere;  the  time  required  for 
this  depending  upon  the  condition  of  the  weather. 

Fig.  106  shows  the  drying  loft  in  a  Morocco  factory,  the  skins 


366 


THE  MANUFACTURE  OF  LEATHER. 


being  hung  on  hooks  which  are  shown  on  the  racks  placed  at 
a  convenient  height  from  the  floor.  When  sufficiently  dry  the 
skins  are  removed  from  the  hooks  and  carried  to  a  room  on 
the  same  floor  as  the  loft,  and  there  assorted  according  to  the 
kind  of  leather  into  which  they  are  to  be  finished.  This  im- 
portant point  having  been  decided  upon,  the  skins  are  removed 
to  the  cellar  and  wetted  down  in  soap-water,  and  while  wet  the 
skins  are  carried  to  a  currier's  beam  and  shaved  with  a  currier's 
knife  on  the  flesh  side,  so  as  to  make  them  of  a  uniform  thick- 
ness, and  also  for  the  purpose  of  having  them  receive  a  better 
finish. 

From  this  point  all  the  skins  pass  to  the  finishing-room,  and 
as  each  kind  of  Morocco  leather  requires  a  different  treatment, 
we  will  now  describe  each  separate  mode  of  finishing  the  various 
kinds. 

FINISHING  IMITATION  OF  FRENCH  KID. 

This  class  of  leather  has  taken  a  high  rank  in  our  country, 
and  it  is  now  generally  conceded  to  be  much  superior  to  the 
genuine  French  kid  for  wear. 

The  skins,  after  being  treated  as  above  described,  are  carried 
to  the  coloring  table  and  colored  on  the  grain  side,  with  an  iron 
and  nutgall-black  having  a  logwood  body,  which  gives  a  clear 
and  bright  black,  and  after  being  blacked  the  skins  are  hung 
up  in  the  loft.  The  skins,  after  the  first  blacking  has  dried, 
next  pass  into  the  finishing-room,  and  the  second  application  of 
black  is  made,  which  is  similar  to  the  first,  with  the  exception 
of  the  nutgalls,  which  are  omitted ;  bichromate  of  potash  is 
sometimes  used  in  this  black,  but  in  small  quantities.  After 
this  second  application  of  color,  the  skins  are  hung  upon  racks 
in  the  finishing-room,  and  left  until  the  color  sets  or  dries,  the 
blackened  side  being  turned  inward,  as  shown  in  Fig.  107, 
which  shows  a  perspective  view  of  the  blacking  tables  and  an 
interior  perspective  view  of  the  finishing-room. 

After  being  removed  from  the  hooks  they  are  next  moistened 
with  a  solution  of  milk  and  water,  and  are  then  ready  to  be 


368 


THE  MANUFACTURE  OF  LEATHER. 


glazed,  which  operation  is  performed  by  machines  of  various 
constructions,  and  which  have  been  heretofore  explained  in 
Chapter  XIX. 

The  skins  are  next  softened  by  hand  with  a  board  and 
scraper,  or,  as  it  is  termed,  a  "softening  slicker." 

They  are  then  oiled  with  the  best  sperm  oil,  which  is  applied 
with  a  rolled-up  flannel  cloth. 

The  skins  are  glazed  two  or  three  times  as  the  case  requires, 
the  oil  is  applied  twice,  and  after  the  last  application  the  imita- 
tion French  kid  is  ready  for  market. 

In  selecting  skins  for  the  production  of  this  class  of  leather, 
their  weight  is  regulated  by  the  demands  of  the  trade,  at  times 
being  light,  and  at  others  heavy.  The  skins  are  also  selected 
for  their  cutting  qualities,  those  which  are  free  from  blemishes 
or  breaks  being,  of  course,  more  valuable  than  those  that  are 
scratched. 

FINISHING  BRUSHED  KID. 

The  finishers  take  the  South  American  goat-skins  from  the 
shaving-beams  and  "  put  them  out,"  and  each  man  will  put  out 
and  black  five  dozen  per  day,  and  after  being  thus  treated  they 
are  hung  in  the  loft  and  dried  by  the  atmosphere. 

The  skins  are  blacked  and  seasoned  with  the  same  prepara- 
tion of  bullock's  blood,  iron,  and  vinegar  black,  which  is  applied 
with  a  piece  of  flannel  cloth  made  into  a  roll.  They  are  then 
wet  over  with  gum-water  and  brushed  with  a  very  soft  brush, 
called  a  "kid-brush."  After  being  hung  in  the  loft  and  dried, 
the  skins  are  next  "  back-boarded,"  then  glassed,  and  next 
rolled  by  a  machine  having  a  steel  roller. 

The  finisher  takes  the  skins  from  the  rolling  machine  and 
scrapes  them  with  a  steel  slicker  in  order  to  loosen  up  the  flesh, 
after  which  the  grain  side  is  oiled  with  the  best  sperm  oil,  which 
is  applied  by  means  of  a  roll  of  flannel  cloth.  The  brushed  kid 
is  now  completed  and  ready  for  market. 

FINISHING  STRAIGHT-GRAINED  GOAT. 

The  first  step  after  shaving  in  finishing  this  variety  of 


KID  OR  MOROCCO  LEATHERS. 


369 


Morocco  is  the  "putting-out,"  which  is  performed  by  working 
over  both  sides  of  the  skin  with  a  steel  slicker.  This  portion 
of  the  work  is  usually  accomplished  by  machinery.  When 
done  by  hand  about  five  dozen  large  skins  or  nine  dozen  small 
ones  are  put  out  by  a  skillful  workman  in  one  day.  The  skins 
thus  treated  in  the  morning  are  placed  in  the  loft,  and  in  the 
afternoon  they  are  "  put  out  the  second  way,"  which  consists 
in  smoothing  the  grain  side.  They  are  drawn  out  and  the 
stretch  removed  in  the  first  operation. 

When  the  skins  are  placed  in  the  loft  they  are  spread  out 
separately  on  the  floor,  as  shown  in  Fig.  108,  and  are  not 
allowed  to  become  too  dry,  and  in  the  afternoon  when  they  are 
"set  out  the  second  time,"  no  water  issues  from  them.  After 
being  set  out  the  second  time  they  are  returned  to  the  loft  and 
placed  on  trestles,  which  are  about  two  feet  six  inches  high,  and 
they  remain  in  this  loft  until  dry,  the  period  of  course  depend- 
ing upon  the  state  of  the  weather. 

The  day's  work  of  each  man  is  kept  separate  from  that  of 
the  others,  and  each  workman  hangs  up  his  own  day's  work  of 
skins,  one  on  each  hook,  and  so  placed  that  none  of  them  touch 
each  other. 

When  dry  the  skins  are  packed  in  piles,  those  that  are  in- 
tended to  be  stained  on  the  flesh  side  being  separated  from 
those  that  are  to  be  pebbled. 

They  are  next  carried  to  the  finishing-room  and  the  rough 
part  of  the  grained  side  is  smoothed  off  with  a  piece  of  fine 
emery  paper,  rolled  so  as  to  expose  the  length  of  the  paper  to 
the  skin. 

This  portion  of  the  work  is  sometimes  accomplished  by 
machinery ;  a  revolving  emery  stone,  such  as  is  used  in  the 
manufacture  of  kid  gloves,  being  employed,  the  dust  being 
blown  from  the  stone  by  a  suitable  fan. 

The  skins  are  next  seasoned,  which  is  accomplished  by  coat- 
ing them  with  a  preparation  of  bullock's  blood,  logwood  boiled, 
cow's  milk,  water,  and  a  small  quantity  of  vinegar  black,  made 
by  treating  iron  with  vinegar,  one  gill  of  the  latter  preparation 
24 


370  THE  MANUFACTURE  OF  LEATHER. 


KID  OR  MOROCCO  LEATHERS. 


371 


being  used  for  a  bucketful  of  "  seasoning,"  which  quantity 
will  season  above  five  dozen  straight-grained  goat-skins.  After 
the  seasoning  has  dried  they  are  regularly  blacked  and  hung  up 
in  the  finishing-room,  as  shown  in  Fig.  100,  and  after  remain- 
ing on  the  hooks  for  about  one  and  one-half-hours,  or  until  the 
dampness  leaves  the  skins,  they  are  rolled  by  machinery.  After 
being  rolled  the  skins  are  again  hung  up  in  the  finishing-room 
and  remain  over  night,  and  in  the  morning  they  are  glazed  on 
a  machine  having  a  glass  roller.  Fig.  109  shows  a  rolling  and 
glazing-room  in  a  morocco  factory. 

The  number  of  skins  rolled  or  glazed  is  from  30  to  50  dozen 
per  day  for  each  machine,  depending  upon  the  speed  at 
which  the  machine  is  driven,  and  also  upon  the  size  of  the 
skins  and  quality  of  the  work.  Some  are  glazed  lighter  than 
others,  in  order  to  give  a  medium  gloss,  but  when  a  high  gloss 
is  desired,  extra  pressure  is  applied. 

After  the  skins  are  glazed  they  are  wetted  in  cold  water  by 
passing  them  through  a  large  tub  holding  about  50  gallons,  and 
the  workman  in  accomplishing  this  takes  two  of  them  and 
places  them  grain  to  grain,  and  grasping  hold  of  the  butt  of  the 
skins  draws  them  slowly  towards  him. 

They  are  next  grained,  which  may  be  performed  either  by 
hand  or  machinery;  if  done  by  hand,  a  graining  board  similar 
to  that  shown  in  Fig.  1  10  is  employed. 


Fio.  109. 


These  graining  boards  are  made  with  a  cork  face,  and  in 
using  them  the  arm  passes  through  the  strap  and  the  hands 
grasp  the  handle. 


KID  OR  MOROCCO  LEATHERS. 


373 


The  object  in  using  this  tool  is  to  raise  the  grain  and  to  make 
the  straight-grained  goat-skins  more  durable,  and  also  has  the 
effect  of  rendering  them  more  pliable  as  well  as  tougher. 

The  skins  are  again  hung  in  the  loft,  usually  above  the  finish- 
ing-room, and  dried  by  the  atmosphere,  which  requires  from 
24  to  48  hours,  according  to  the  state  of  the  weather.  After 
this  drying  they  are  again  grained,  which  has  the  tendency  to 
raise  the  figure  and  further  mellow  them.  All  the  graining 
is  done  on  the  grain  side ;  but  after  the  second  graining  they 
are  "  back- boarded  "  on  the  flesh  side,  which  has  a  tendency 
to  make  the  figure  more  uniform  as  well  as  to  still  further  soften 
the  skins. 

An  application  of  best  sperm  oil  to  the  grain  side  of  the 
skins  completes  the  finishing  of  straight-grained  goat,  and  as 
the  oil  is  immediately  absorbed  by  the  pores,  the  skins  are  at 
once  ready  for  market. 

From  the  time  that  they  enter  the  finishing  shop  to  the  time 
that  the  straight-grained  goat  is  ready  for  market,  the  period  is 
about  seven  to  ten  days,  being  shortest  in  good  drying  weather 
and  longest  when  the  condition  of  the  atmosphere  is  not  favor- 
able. There  is  also  a  grade  of  Morocco  leather  known  as 
"  caracal,"  which  is  straight-grained  calf,  and  its  peculiarities 
are  pliability,  toughness,  gloss,  and  superior  finish.  This 
leather  has  a  fancy  finish,  and  its  introduction  into  the  trade 
has  been  but  to  a  limited  extent. 

FINISHING  PEBBLE-GRAIN  GOAT. 

The  difference  in  finishing  pebble-grain  goat  fromstraight- 
grained  is  that  the  first  named  is  "cut"  four  ways  in 
the  process  of  hand-finishing,  in  the  softening,  and  in  the 
"springing  up;"  but  in  "back-boarding"  it  is  cut  two  ways 
only.  The  skins  are  pebbled  on  the  same  machine,  but  not 
with  the  same  roller  that  is  used  for  straight  graining. 

FINISHING  OIL  GOAT. 

In  finishing  "oil  goat,"  after  the  skins  have  been  "put  out 


374 


THE  MANUFACTURE  OF  LEATHER. 


the  second  way"  and  blacked,  they  are  then  stuffed  with 
dubbing  on  the  flesh  side.  The  dubbing  is  composed  of  one- 
half  oil  and  one-half  tallow  when  used  during  the  winter  time; 
but  in  the  summer  more  tallow  than  oil  is  used.  They  are 
then  hung  up  to  dry,  after  which  they  are  grained  three  ways 
and  then  treated  to  a  coat  of  dubbing  on  the  grain  side,  after 
which  they  are  flattened  down  on  the  grain  side  with  a  dull 
slicker,  and  after  being  treated  with  a  coat  of  fine  sperm  oil 
which  completes  the  finishing,  the  oil  goat-skins  are  then 
measured  and  marked  ready  for  the  trade. 

This  class  of  Morocco  leather  is  more  water-proof  than  the 
other  grades  of  sumac-tanned  skins,  and  is  used  in  a  small  way 
for  ladies'  heavy  wear,  and  sometimes  boys'  boots  are  made 
from  it. 

The  heaviest  skins  are  used  for  this  kind  of  leather,  and  the 
kinds  commonly  employed  are  Tampico,  Capes,  and  Patnas. 

COLORING. 

William  M.  Norris,  of  Princeton,  N.  J.,  gives  the  following 
information  about  coloring: 

"  At  the  present  time,  when  the  greatest  economies  are  essen- 
tial, it  would  doubtless  occur  to  some  manufacturers  of  glazed 
kid  that  a  saving  might  be  effected  if  they  themselves  made 
their  own  "  Black,"  "  Sig,"  "Seasoning,"  "  Stains,"  &c.  Even 
if  successful  in  producing  good  articles,  which  is  very  doubtful, 
the  saving  is  infinitesimal  and  the  economy  a  most  costly  one. 
Take  "Black"  for  example  ;  a  barrel  of  "Norris  Black"  will 
color  about  600  dozen  skins  and  costs  about  $7.50.  Say  these 
skins  measure  50  feet  to  the  dozen,  we  will  then  have  30,000 
feet  of  skins,  and  the  black  therefor  will  cost  TV  of  a  cent  a 
foot.  Provided  the  black  made  by  the  leather  manufacturer 
himself  costs  nothing,  the  saving  is  hardly  visible ;  the  differ- 
ence in  color  will,  however,  be  quite  apparent. 

"  It  is  in  fact,  determined  by  long  experience,  that  in  all  manu- 
facturing operations  the  fewer  the  articles  made,  and  the  more 
attention  is  concentrated  on  these  few,  the  greater  perfection 


KID  OR  MOROCCO  LEATHERS. 


375 


will  be  attained.  A  specialist  in  the  manufacture  of  coloring 
materials  for  leather  who  thoroughly  understands  the  proper- 
ties and  relations  of  the  raw  materials  employed,  and  the  best 
methods  of  combining  them,  will  produce  far  better  and  more 
economical  products  than  the  individual  leather  manufacturer." 

Mr.  Norris  makes  a  black  which  is  a  great  favorite  for  chrome 
tanned  leather. 

DONGOLA  CALF. 

Make  packs  of  convenient  number  according  to  size  of  soaks 
and  limes,  200  or  250  skins  of  9  to  12  lbs.  or  7  to  9  lbs.  or  more 
of  small  stock.  Soak  thoroughly  and  break  well,  either  by  hand 
or  machine.  Trim  and  re-soak  if  necessary,  before  going  to 
limes.  As  red  arsenic  has  a  very  softening  effect  in  liming 
skins  it  is  generally  used  on  this  class  of  work  in  connection  with 
lime.  Make  up  limes  in  proportion  of  85  parts  lime  and  1  5 
parts  arsenic  to  400  to  500  gallons  water. 

The  first  lime  should  be  weak  or  four  per  cent.  Stock  should 
be  hauled  daily  and  strengthened  a  little,  keeping  the  above 
proportion  of  lime  and  arsenic.  Lime  eight  or  ten  days. 
When  hair  slips  freely,  unhair  by  machine  or  hand,  carefully. 
Wash  in  hide  mill  or  paddle  vat  until  stock  is  fairly  clean  of 
lime.  Flesh  on  machine  ;  fine-hair  grain  on  beam  and  shave 
heads  down  some.  Wash  again  and  then  bate  fairly  low.  Some 
tanners  use  solid  bate  for  this  work  ;  others,  a  liquid  bate. 
Any  of  the  known  bates  are  good. 

After  bating,  work  well  on  flesh,  and  slate  the  grain.  Then 
rinse  and  bran-drench  in  mill  for  45  minutes.  After  which, 
drain  and  put  in  tan.  Make  up  liquor  in  same  way  as  for  goat 
tannage,  holding  calf  in  tan  48  hours  longer  than  on  goat. 
After  eight  days  in  tan,  haul  and  drain  well  over  night  and  oil 
in  mill.  To  every  150  skins  use  four  gallons  (half  cod  and  half 
neatsfoot  oil).  Run  one  hour  in  oil,  then  remove  from  mill  and 
put  in  loft  to  dry. 

When  dry,  pack  down  five  or  six  days,  then  wet  back  in  mill 
to  shave,  using  tan  liquor  to  dampen  stock,  and  don't  get  it  too 


376 


THE  MANUFACTURE  OF  LEATHER. 


wet.  After  shaving,  re-tan  in  mill  four  or  five  hours,  in  four  or 
five  per  cent,  strength  of  liquor.  Then  put  on  hooks  to  dry. 
When  dry,  wet  down  in  mill  to  color. 

To  every  five  dozen  skins  use  three  pails  water  and  six 
gallons  fat  liquor.  If  a  good  yellow  flesh  is  desired,  dissolve 
four  ounces  auramine  in  boiling  water  and  add  it  to  fat  liquor. 
Run  stock  45  minutes  in  fat  liquor,  after  which  color  and  strike 
out  on  grain  and  oil  off  with  half  cod  and  half  neatsfoot  oil. 

After  oiling  put  in  hot  room  to  dry.  When  dry  lay  in  dust 
to  dampen  for  staking.  Stake  well  on  machine,  flesh  up.  Air 
off  and  pad  grain,  then  put  in  perch  and  arm-stake  flesh  and 
slate  grain.  Iron  and  trim,  and  measure.  Then  oil  off,  and 
pack  down  in  oil  over  night  black  to  black.  The  next  day 
wipe  off  grain  with  flannel,  and  stock  is  finished,  and  may  be 
sorted  and  dozened  to  ship  away. 

THE  OLD   PROCESSES  OF  CONVERTING  GOAT-SKINS    INTO  "  DONGOLA  "  AND 
OTHER  FINE  LEATHERS. 

It  is  the  purport  of  this  section  to  treat,  not  of  the  more 
modern  tannages,  but  of  the  earlier  brands  that  were  for  a 
number  of  years,  and  very  justly,  regarded  as  standard — we 
refer  to  the  "  Dongola  "  and  preceding  tannages. 

The  different  processes  through  which  goat-skins  pass  in 
their  conversion  into  Dongola  are :  Soaking,  milling,  liming, 
unhairing,  fleshing,  washing,  bating,  slating,  bran  drenching, 
tanning,  striking  out,  drying,  assorting  for  finishing,  wetting, 
shaving,  dyeing,  glazing  and  assorting  for  weight  and  grade. 

The  skins  come  to  the  factories  in  bales — the  bales  contain- 
ing from  100  to  600  skins  each — and  are  placed  in  the  storage 
room.  They  are  then  in  a  dry  state.  The  first  treatment  to 
which  they  are  subjected  is  that  of  "  soaking,"  which  consists 
of  placing  the  skins  in  vats  filled  with  cold,  clear  water.  Here 
they  remain  for  from  24  to  48  hours,  according  to  the  weight 
or  texture  of  the  skins.  Those  possessing  a  hard  fibre  will  re- 
quire a  longer  time  to  become  thoroughly  softened  than  those 
of  a  softer  texture. 


KID  OR  MOROCCO  LEATHERS. 


377 


When  thoroughly  soaked  they  are  taken  out  and  placed  in 
the  "  mill."  This  is  a  contrivance  which  consists  of  one  or  two 
large  stones  revolving  vertically  on  a  wooden  pit.  The  stones 
are  usually  immense  granite  rollers,  about  four  feet  in  diameter 
and  from  eight  to  ten  inches  thick.  The  pit  around  which  the 
perpendicular  stone  revolves  is  about  two  feet  deep.  After 
"milling"  they  are  washed  until  they  are  thoroughly  soft  and 
pliable — in  fact,  in  much  the  same  condition  as  when  they  are 
taken  off  the  backs  of  the  animals.  The  skins  while  milling  are 
placed  under  the  roller  by  a  workman,  who  occasionally  turns 
them  from  side  to  side,  and  brings  them  effectually  under  the 
operations  of  the  revolving  granite  block.  Of  course  there  are 
other  means  of  reducing  skins  to  the  proper  state  now  in  use. 

The  next  process  is  that  of  "  liming."  The  skins  are  per- 
mitted to  remain  in  the  limes  usually  from  twelve  to  fifteen 
days,  according,  as  in  the  case  of  other  processes,  to  the  texture 
of  the  skins.  The  object  of  the  "  liming "  is  to  thoroughly 
loosen  the  hair  on  the  skin,  so  that  it  may  be  afterwards  rapidly 
and  completely  removed. 

We  now  follow  the  skins  to  the  unhairing  room,  where  they 
are  placed  on  unhairing  beams  and  depilated  and  fleshed  by 
workmen  who  use  for  the  process  long,  rounded  knives  pecul- 
iarly shaped  for  the  purpoe.  All  the  processes  through  which 
the  skins  have  up  to  this  stage  passed  prepare  them,  by  soften- 
ing, removing  all  impediments  and  opening  the  pores,  to  per- 
mit the  ready  entrance  of  the  tanning  ingredients.  The  skilled 
tanner  will  be  ever  on  the  alert  in  his  intelligent  watchfulness 
through  all  these  preparatory  stages,  and  will  exercise  his  dis- 
cretion as  to  duration  of  time,  etc.,  according  to  the  heft  of  the 
raw  stock,  the  temperature  of  the  weather  and  the  condition  of 
the  water. 

From  the  unhairing  room  the  skins  pass  to  the  "  wash-mill," 
where  they  receive  a  thorough  washing,  removing  all  adhering 
lime,  and  preparing  them  for  subsequent  treatment. 

The  next  process  to  which  they  are  treated  is  "bating." 
The  bate  is  usually  composed  of  dog  munure,  dissolved  in 


378 


THE  MANUFACTURE  OF  LEATHER. 


slightly  heated  water.  This  process  is  now  usually  designated 
"  puring."     The  skins  are  left  in  the  bate  for  about  ten  hours. 

They  are  now  ready,  on  removal  from  the  bate,  for  the  slat- 
ing room.  Here  is  completed  whatever  may  remain  unfinished 
in  the  unhairing  room  by  removing  every  particle  of  hair  that 
may  still  adhere  to  the  skin.  The  tool  used  in  this  process  is 
called  a  "slater,"  which  in  a  large  degree  resembles  a  "  slicker." 

The  skins  are  next  subjected  to  the  bran-drench.  The  drench 
is  composed  of  bran  and  water.    It  is  slightly  heated. 

In  the  old  sumach  tannage  the  skins  were  next  sewed  in  bags 
and  filled  with  sumach  liquor,  grain  side  out.  They  were  piled 
up  in  a  heap  in  a  vat  filled  also  with  sumach  liquor.  In  the 
course  of  one  day  these  skins  were  filled  and  emptied  five  differ- 
ent times,  in  order  that  they  might  be  thoroughly  and  evenly 
tanned.  After  this  they  were  transferred  to  the  "  striking  out" 
room.  The  "striking  out"  was  performed  on  mahogany 
tables,  slanting  downward  from  the  operator  at  an  angle  of 
about  45  degrees.  For  this  purpose  the  "slicker,"  referred  to 
in  a  preceding  operation,  was  used.  In  this  process  the  size  of 
the  skin  is  somewhat  enlarged,  and  any  adhering  "  fleshing," 
tannin  or  water,  completely  removed.  The  skins  during  this 
operation  became  smooth  and  even,  and  the  work  of  beautifica- 
tion — if  the  term  be  allowable — commenced. 

After  being  "struck  out"  the  skins  were  dyed  or  "blacked," 
usually  on  a  table,  the  present  method  of  dyeing,  of  course,  not 
being  used. 

We  next  find  the  skins  in  the  "  drying  room,"  where  they  were 
suspended  from  hooks  in  a  row  along  the  ceiling.  The  time 
used  for  drying  was  regulated  largely  by  the  condition  of  the 
weather. 

When  dry  they  were  assorted  for  particular  finishes,  each 
skin  being  set  apart  for  the  finish  to  which  it  was  best  suited. 
After  being  finished  they  were  again  assorted  for  quality  and 
weight,  when  they  were  ready  for  the  inspection  of  buyers. 

Thus  it  will  be  seen  how  very  varied  and  critical  were  the 
.processes  through  which  a  goat-skin  had  to  pass  during  its 
■conversion. 


CHAPTER  XXIV. 


OAK  TANNED  SOLE  LEATHER — UNSCOURED   AND  SCOURED 
LEATHER — CUT  SOLES. 

The  hides  used  are  the  packer  hides  from  the  packing 
houses  in  Chicago,  Kansas  City,  Sioux  City,  St.  Louis,  Omaha, 
Los  Angeles  and  other  points.  Country  hides  and  South 
American  hides  are  also  employed. 

Texas  hides  are  usually  branded  and  are  made  mostly  into 
unscoured.  Those  which  are  unbranded  and  those  having 
only  a  few  brands  not  very  marked  are  used  for  scoured 
leather. 

South  American  hides  make  a  very  clear  grain  scoured 
leather,  which  is  used  by  manufacturers  of  best  men's  shoes. 

The  hides  are  placed  in  the  "  soaks,"  in  which  they  remain 
about  three  days,  the  period  depending  upon  their  condition 
and  upon  the  temperature  of  the  water  in  the  "  soaks."  Warm 
water  requires  proportionately  less  time  than  cold  water.  Some 
tanners  claim  that  warm  water  will  soak  hides  more  efficiently, 
and  that  the  filth  etc.,  can  be  better  removed,  or  the  hide  better 
cleansed  for  the  "  limes,"  which  is  very  important.  It  is  said 
that  the  loss  of  "hide  substance  "  is  also  less,  because  less  time 
is  required  for  soaking. 

The  water  in  the  "soaks"  is  changed  with  each  pack  of  hides. 
To-day,  careful  tanners  withdraw  the  packs  after  the  first 
day's  soaking,  run  off  the  dirty  water,  and  replenish  with  fresh. 
The  day  of  putrid  soaks  is  past.  Tanners  are  saving  money 
by  keeping  their  soaks  clean  and  not  leaving  the  hides  in 
rotten  water.    It  is  a  small  point,  but  worth  remembering. 

The  hides  may  be  fleshed  at  this  stage — called  "  green 
fleshing,"  or  they  go  into  the  "  limes  "  and  remain  for  about 

(  379  ) 


38o 


THE  MANUFACTURE  OF  LEATHER. 


five  days  or  more  and  are  then  unhaired  and  fleshed,  as  de- 
sired. 

While  in  the  "  limes  "  the  hides  are  changed  each  day  by 
means  of  a  power  reel  into  stronger  lime,  and  when  the  hair  is 
loosened  they  are  unhaired  and  afterwards  fleshed,  and  then 
thrown  into  a  vat  of  clear  water  and  left  to  remain  over  night. 

In  the  morning  the  hides  are  removed  from  the  clear  water 
and  "  grained,"  which  process  consists  in  scraping  the  hides  on 
the  grain  side  in  order  to  cleanse  them  more  thoroughly  from 
the  lime  remaining  in  the  pores. 

After  being  "  grained  "  the  hides  are  again  placed  in  clear 
water,  where  they  remain  for  three  or  four  hours,  which  com- 
pletes the  beam-house  work. 

In  some  tanneries  the  unhairing  and  fleshing  is  done  entirely 
by  machinery  ;  the  tanners  claiming  that  the  cost  of  the  beam 
house  work  is  only  about  one  third  as  much  when  done  in  this 
way  compared  to  hand  labor.  Unhairing  and  fleshing  machines 
are  shown  in  Chapter  VIII. 

The  hides  after  being  unhaired  and  fleshed  by  machinery  are 
usually  bated  over  night  in  a  bate  made  by  adding  about  one 
gallon  of  molasses,  or  more,  to  the  vat  of  water. 

Some  tanners  still  flesh  and  unhair  by  hand,  because  the 
machines  they  tried  years  ago  for  these  purposes  were  crude 
and  unsatisfactory.  Some  tanners  forget  that  the  modern 
machines  are  successful,  and  decidedly  economical  to  use. 
Small  tanners  may  not  do  enough  business  to  encourage  their 
buying  beam-house  machinery;  but,  no  matter  how  large  or 
small  their  place  may  be,  before  abandoning  all  hope  of  using 
machines  let  the  tanner  ask  the  advice  of  clever  and  courteous 
machinery  men,  who  may  be  able  to  give  some  valuable  informa- 
tion. Some  tanners  can  unhair  by  machine  all  right,  but  find  it 
better  to  flesh  by  hand,  as  they  get  better  sole-leather  in  this  way. 

The  sole-leather  tanners  that  we  know  do  not  leave  the  hides 
in  lime  for  more  than  two  or  three  days.  But  during  this  time 
they  are  handled  several  times,  and  the  limes  kept  plunged  up. 
The  scheme  of  giving  limed  hides  a  warm  bath,  say  100  to  1 10 


OAK  TANNED  SOLE  LEATHER. 


381 


degrees,  during  the  night  previous  to  unhairing,  seems  to  work 
pretty  well.  The  hair,  after  the  hides  have  been  pushed  some- 
what quickly  through  the  limes  and  warm  water,  may  come  off 
hard  on  the  beam,  but  this  is  safer  for  the  tanner  than  when  the 
lime  has  so  dissolved  the  hide  matter  after  prolonged  liming 
that  the  hair  slips  off  almost  by  itself.  This  is  all  very  nice  for 
the  beamsters,  particularly  when  they  are  on  piece  work  ;  but  we 
would  prefer  giving  the  men  a  fair  day's  pay,  so  that,  even  if 
the  hair  comes  off  hard  and  slow,  they  would  not  be  justified 
in  complaining. 

Some  tanners  are  too  economical  in  working  the  grain,  after 
they  unhair.  Whether  machines  or  hand  are  used,  clean,  bright 
leather  cannot  be  obtained  unless  the  grain  is  carefully  and 
thoroughly  scudded.  There  are  establishments  where  hides 
for  sole  leather  are  put  through  a  mild  bate  before  being  fine- 
haired  and  worked  on  the  grain.  It  is  claimed  that  the  bating 
by  its  assistance  in  expelling  lime  from  the  fibre  tends  to  make 
softer  and  smoother  leather. 

Union  leather  is  liable  to  be  cloudy  and  dirty  on  the  grain 
on  account  of  careless  beam-work.  Bad  salt  is  also  an  enemy 
of  clean  grain.  Hide  dealers  as  a  rule  are  willing  to  accommo- 
date their  customers,  and  it  is  generally  agreed  by  well- posted 
men  that  hides  cured  by  Syracuse  coarse  salt  are  not  so  liable 
to  have  dirty  grain  as  when  fine  salt  or  harsh  mined  salt  is 
used.  Tanners  should  ask  their  hide  men  to  use  only  the  best, 
cleanest  and  mildest  salt.  Salt-stained  leather  is  a  nuisance 
and  an  expensive  eye-sore,  and  might  be  avoided  if  the  proper 
salt  were  used  in  curing.  Borax  is  the  best  agent  for  preserv- 
ing hides.  One  pound  of  borax  will  go  as  far  as  five  pounds 
of  salt.    When  borax  is  used,  there  are  no  stains  of  any  kind. 

When  sweats  are  employed  it  is  often  good  policy  to  give 
the  man  in  charge  of  them  extra  wages  of  a  dollar  or  two  each 
week.  This  small  premium  will  be  a  great  inducement  to  him 
to  attend  zealously  to  his  work.  There  will  be  times  at  dead 
of  night  when  he  will  have  to  enter  the  pits  and  unhook  the 
hides,  so  as  to  stop  the  decomposition.    In  putting  sweated 


382 


THE  MANUFACTURE  OF  LEATHER. 


hides  through  the  hide-mill,  there  should  be  no  hurry.  While 
there  is  no  need  to  move  the  tender  stock  about  too  much,  the 
work  should  be  well  done.  In  this  connection  we  would  urge 
that  after  soaking  dry  hides  they  ought  to  be  specially  well 
milled,  so  as  to  prevent  any  hard  spots  remaining. 

It  should  be  the  duty  of  every  tanner  to  keep  a  ledger  ac- 
count of  each  lot  of  hides  put  through  the  tannery.  He  ought 
to  isolate  each  important  lot  of  hides  received  from  each  dealer. 
These  should  be  marked  with  a  letter  or  number  and  carefully 
followed  through  the  tannery  right  to  the  weighing-out  scale  in 
the  leather  lofts.  It  could  then  be  easily  discovered  which 
dealer  it  was  more  profitable  to  buy  from.  These  suggestions 
may  cause  careful  tanners  to  smile,  but  they  would  be  surprised 
if  they  knew  how  many  tanners  there  are  who  take  chances  on 
what  they  are  doing,  trusting  to  luck  to  come  out  all  right. 

The  hides  are  next  suspended  in  "rockers,"  which  operation 
is  the  first  stage  of  the  tanning  proces,  its  object  being  the  re- 
moval of  the  lime  still  remaining  in  the  grain,  the  swelling  of 
the  hide  and  setting  of  the  color.  The  hides  are  rocked  from 
two  to  three  times  per  day.  They  remain  in. the  "rockers" 
from  seven  to  ten  days,  depending  upon  the  number  of  "rock- 
ers "  and  hides  worked  per  day. 

The  hides  are  now  taken  out  of  the  "rockers"  and  rehung 
on  sticks  in  the  "  handlers,"  where  they  remain  for  ten  to  four- 
teen days,  depending,  as  before,  upon  the  number  of  vats  and 
hides  worked  per  day. 

In  some  tanneries  the  hides  remain  undisturbed  on  the  sticks 
in  the  same  liquor  for  the  required  period  ;  while  in  others  the 
liquor  is  changed  regularly.  Again,  in  some  tanneries  the 
hides  are  handled  from  one  vat  into  another,  that  is,  the  hides 
are  moved  forward  to  meet  the  stronger  liquor. 

It  should  be  noted  that  the  quality  of  leather  is  made  in  the 
"  rockers"  and  "  handlers,"  that  is,  the  color,  plumpness,  etc. 

The  liquors  supplied  to  the  "rockers"  must  be  mellow  and 
not  strong.  The  strength  of  the  liquors  must  be  regulated  by 
the  number  of  pits  used,  so  that  the  green  hides  should  have 


OAK  TANNED  SOLE  LEATHER. 


385 


sufficient  acid  in  the  pit  to  purge  it  of  lime  and  properly  start 
the  plumping. 

The  liquor  going  on  the  hides  in  the  "handlers"  is  consid- 
erably stronger,  judgment  being  used  as  to  the  strength,  which 
is  governed  by  the  extent  to  which  the  tanning  has  progressed 
in  the  "  rockers." 

After  having  been  in  the  "handlers"  the  required  time,  the 
hides  are  placed  upon  a  truck  and  conveyed  to  the  yard 
proper,  or  "lay-away"  yard,  where  the  tanning  process  is 
completed.  The  "lay-away  vats"  are  of  different  sizes  in  dif- 
ferent tanneries;  the  common  size  being  nine  feet  long,  seven 
feet  wide  and  six  feet  deep  ;  but  those  in  the  yard  of  The  Amer- 
ican Oak  Leather  Company,  at  Cincinnati,  Ohio,  are  eight 
feet  deep.  In  these  vats  the  hides  are  placed  one  by  one,  spread 
out  flat,  and  a  thin  layer  of  dry  ground  bark  is  sprinkled  over 
each  hide,  in  order  that  the  liquor  may  circulate  uniformly. 
This  bark  should  not  be  ground  too  finely,  or  it  will  pack  so 
tightly  as  to  prevent  the  circulation  of  the  liquor  which  would 
result  in  imperfectly-tanned  leather. 

After  the  hides  have  "  laid-away  "  for  a  sufficient  length  of 
time  to  extract  the  tannin  partially  out  of  the  "  liquor,"  they 
are  taken  out  and  the  liquor  run  off  into  a  receiver  through 
wooden  pipes  and  pumped  by  steam  power  back  to  the  leachesr 
where  it  passes  through  the  bark  and  is  re-strengthened  and 
then  run  in  new  liquor  into  the  tan  vats,  and  the  hides  are  then 
put  back  as  before. 

Each  pack  is  usually  "  laid-away,"  that  is,  given  new  liquor 
from  four  to  five  times,  the  light  hides  are  "laid-away"  four 
times  and  the  heavy  hides  five  times,  the  whole  operation  in  the 
"  lay-aways "  extending  over  a  period  of  nearly  four  months 
for  light  leather  and  four  months  and  a  half  for  heavy  leather. 

The  following  schedule  is  from  one  of  the  largest  and  most 
successful  tanneries  in  the  country,  and  it  will  give  an  idea  of 
the  time  and  strength  of  liquor  employed  in  each  layer: 


THE  MANUFACTURE  OF  LEATHER. 


Heavy  Hides. 


Layer. 


Length 
of  time. 


Strength 
of  liquor. 


1st    14  days. 

2d   20  " 

3d   25  " 

4th    30  " 

5th   1    50  " 

139  days. 


30  deg. 
28  " 
30  " 
36  " 
45  " 


Light  Hides. 


Layer. 


Length 
of  time. 


Strength 
of  liquor. 


1st   14  days. 

2d   20  " 

3d  I    3°  " 

4th  1    50  " 

114  days. 


30  deg. 
30  " 
34  " 
45  " 


Hides  after  coming  from  the  "  handlers"  go  into  first  layer. 
The  liquor  used  for  this  layer  is  the  liquor  taken  from  a  tanned 
pack,  and  is  fifty  days  or  more  old  and  never  very  sour.  This 
liquor  is  strengthened  with  extract  to  about  30  degrees  barko- 
meter,  and  heavy  hides  are  laid  away  for  fourteen  days  with 
bark  as  has  been  described.  The  pack  of  hides  is  then  drawn 
and  then  laid-away  again  in  a  fresh  sweet  bark  liquor  which 
has  been  strengthened  with  extract  to  about  28  degrees,  where 
they  remain  about  twenty  days.  Pack  is  again  drawn  and  put 
with  the  third  layer,  which  is  a  fresh  sweet  bark  liquor  streng- 
thened with  extract  to  about  30  degrees  barkometer,  where 
they  remain  for  about  twenty-five  days.  Pack  is  again  drawn 
and  put  into  the  fourth  layer,  which  is  fresh  sweet  bark  liquor 
strengthened  with  extract  to  about  36  degrees  barkometer,  and 
where  they  remain  for  thirty  days.  Then  the  pack  is  again 
drawn  and  placed  in  the  fifth  layer,  which  is  fresh  sweet  bark 
liquor  strengthened  with  extract  to  45  degrees  barkometer, 
where  they  remain  for  fifty  days. 

The  light  hides  are  laid  away  only  four  times,  the  length  of 
the  layers  and  strength  of  the  liquors  being  indicated  in  the 
schedule.  The  strength  of  the  liquors  should  be  determined 
by  chemical  analysis,  which  shows  that  the  amount  of  tanning 
substance  per  degree  barkometer  in  sweet  fresh  liquors  in- 


OAK  TANNED  SOLE  LEATHER. 


385 


creases  directly  as  the  degree  of  barkometer.  As  an  example : 
A  ten  degree  chestnut  oak  bark  liquor  contains  about  1.25  per 
cent,  of  tanning  substance,  a  twenty  degree  liquor  contains 
about  2.50  per  cent,  of  tanning  substance,  and  so  on. 

The  hides  after  being  tanned  are  taken  out  of  the  vat  and 
split  into  sides.  The  sides  are  now  rinsed  in  the  liquor  in 
which  the  tanning  has  been  finished  and  are  then  piled  to  drain, 
say  over  night.  The  sides  are  then  oiled  on  the  grain  side  with 
cod  oil,  fish  oil,  or  a  mixture  of  mineral  and  fish  oils.  The  oil 
is  applied  with  a  sheep-skin  swab  or  a  cloth  swab. 

The  sides  are  now  hung  up  on  sticks,  which  are  partially 
rounded  upon  the  edge  that  comes  in  contact  with  the  leather, 
in  the  drying  room  to  dry.  The  sticks  upon  which  the  sides  are 
suspended  in  the  drying  loft,  are  2  in.x  2  in.  and  8  ft.  long ;  two 
sides  are  suspended  upon  each  stick  about  one  foot  apart,  and  a 
passage-way  6  feet  wide  is  maintained  in  the  centre  of  the  loft, 
and  on  each  side  of  this  passage-way  two  rows  of  sticks  for 
holding  the  sides  are  placed. 

The  drying  room  is  heated  with  a  suitable  steam  pipe 
system  so  arranged  as  to  distribute  the  heat  gently  and  uni- 
formly, and  fans  so  placed  as  to  draw  off  the  moisture  from  the 
drying  room  as  fast  as  it  is  given  off  by  the  leather. 

In  drying  sole  leather  it  is  very  desirable  that  too  much  light 
should  not  be  allowed  to  enter  the  loft,  as  it  is  injurious  to  the 
color. 

The  temperature  of  the  drying  loft  is  kept  at  700  to  8o°  F., 
care  being  observed  not  to  get  the  temperature  too  high.  In 
the  summer  time  the  loft  is  kept  closed  and  the  room  darkened, 
some  tanners  even  going  to  the  expense  of  having  double 
shutters  on  the  windows. 

With  an  intelligently  constructed  drying-loft,  sole  leather  wet 
from  the  vats  can  be  dried  in  forty-eight  hours,  ready  for  the 
roller,  but  some  tanners  prefer  to  dry  it  for  a  longer  time.  When 
the  sides  are  thoroughly  dry  they  are  taken  to  the  rolling  room, 
which  is  well  lighted,  and  dipped  in  clear  cold  water,  and  when 
the  leather  is  hard  it  is  dipped  in  a  warm  water  bath. 
25 


386 


THE  MANUFACTURE  OF  LEATHER. 


The  sides  are  now  piled  and  covered  and  allowed  to  "  sammy" 
or  become  of  a  uniform  temper.  They  are  then  rolled  and 
hung  up  in  the  loft  to  dry,  and  when  dry  are  ready  to  be  sorted 
for  market. 

The  above  description  is  for  leather  with  a  bloom. 

The  question  is  often  asked  us:  "  How  much  or  what  per 
cent,  of  rough  leather  can  be  obtained  from  the  various  grades 
of  hides."    Our  answer  is  as  follows: 


For  scoured  leather  the  hides  are  split  and  rinsed  the  same  as 
has  been  described  for  the  unscoured  leather.  The  sides  are 
sometimes  milled,  and  then  they  are  scoured  by  means  of  a 
Monk  Scouring  Machine,  shown  in  Figs.  50  and  56.  The  sides 
are  now  drained  and  oiled  as  has  been  described  for  unscoured 
leather,  or  they  may  be  oiled  in  a  mill.  They  are  then  hung 
up  to  dry  and  when  dry  they  are  dipped  in  water,  "  sammied," 
rolled  and  hung  up  to  dry,  and  when  dry  rolled  again,  when 
they  are  ready  to  go  to  the  sorter  and  be  selected  for  the 
market. 

This  description  is  intended  to  cover  modern  tanneries  which 
use  tanning  extract.  In  tanneries  where  no  extract  is  employed 
the  liquor  may  be  several  degrees  lighter,  and  the  length  of  the 
"  lay-aways  "  slightly  increased. 

In  some  tanneries  the  hides  are  split  into  sides  either  as  they 
come  out  of  the  soaks  or  out  of  the  limes,  especially  when  the 
tannery  has  smaller  size  vats  than  7x9  feet. 

The  tanning  of  the  whole  hide  is  more  economical  in  labor 
in  the  yard,  but  the  tanning  of  sides  is  more  economical  in  the 
beam-house  work. 

The  rolling  machine  shown  in  Fig.  1 1 1  is  the  kind  generally 
employed  for  rolling  sole  leather.  The  rollers  of  these 
machines  are  made  of  brass,  and  are  six  inches  in  diameter  and 
six  inches  face  or  length,  and  are  turned  to  a  true  surface  and 


Oak. 


Hemlock. 


Green  Salted  Hides 
Dry        "  " 
Flint  " 


about  50  per  cent. 


55  to    80  per  cent. 
112  to  122  " 
160  to  175  " 


OAK  TANNED  SOLE  LEATHER. 


387 


work  into  roller  beds  on  concaves,  which  are  also  of  brass  and 
planed  true  to  the  radius  or  length  of  the  vibrator  or  pendulum 
of  each  machine. 

The  pressure  of  the  rollers  upon  the  leather  is  imparted  by 
means  of  levers  connected  with  the  vibrator  or  pendulum  of 
each  machine,  and  controlled  by  a  lever  worked  by  the  foot  of 

Fig.  hi. 


 £%\ 

-   wkL 

the  operator.  The  hook  to  which  the  foot-piece  is  connected  is 
shown  in  the  illustration  of  the  machine.  After  the  roller  has 
passed  over  a  portion  of  the  side  two  or  three  times,  it  is  shifted 
by  the  hand  of  the  operator  until  all  parts  are  successfully 
operated  upon. 

These  machines  are  built  by  the  Eureka  Bark  Mill  Co.,  Lan- 
caster, Pa.  J.  A.  Brownell,  Binghamton,  N.  Y.,  builds  a  good 
under  pressure  sole  leather  rolling  machine. 


CUT  SOLES. 


By  the  competition  in  trade  many  tanners  are  forced  to  cut 
soles,  which  are  sold  direct  to  shoe  manufacturers.    Men's  out- 


388 


THE  MANUFACTURE  OF  LEATHER. 


soles  are  cut  from  packer  Texas  hides,  scoured  oak  barks. 
Women's  outsoles  are  cut  from  scoured  oak  barks  from  packer 


native  hides.  The  inner  sole  stock  comes  from  the  same  class 
of  hides,  but  from  that  portion  which  is  not  good  enough  for 


OAK  TANNED  SOLE  LEATHER. 


389 


outer  soles.  Goodyear  insoles  are  cut  of  an  oak  bark  especially 
tanned  and  finished  for  that  purpose.  Counters  are  made  flat 
and  moulded.  McKay  and  Goodyear  counters  are  made  out 
of  scoured  oak  bellies.  Counters  for  Turn  shoes  are  cut  from 
light  scoured  oak  shoulders. 

One  of  the  largest  dealers  in  leather  and  findings  recently 
said  that  trade  in  sole  leather  is  carried  on  very  differently  from 
a  few  years  ago.  Then  he  had  in  his  store  constantly  not  less 
than  2,000  sides.  Now  he  thinks  he  is  overstocked  if  he  has 
more  than  200  on  hand.  The  reason  of  this  is  that  shoemakers 
buy  most  of  their  leather  already  cut.  They  can  obtain  it 
cheaper  this  way,  and  the  bother  of  cutting  is  done  away  with. 
"Some  of  my  customers  in  the  immediate  vicinity,"  says  he, 
"do  not  carry  any  leather  on  hand.  When  they  get  a  pair  of 
shoes  to  tap  they  come  in  and  buy  the  soles  for  them." 

An  interior  view  of  a  cut  sole  factory  of  Ackerman  &  Brum- 
mel,  New  York  City,  is  shown  in  Fig.  112. 


CHAPTER  XXV. 


HARNESS  AND  BELTING  LEATHER. 

Native  steer  and  heavy  cow  hides,  free  of  brands  and  other 
blemishes,  are  used  for  this  variety  of  leather.  The  beam-house 
preparation  of  the  hides  does  not  differ  materially  from  that  of 
hides  intended  for  heavy  upper  leather,  except  that  the  liming 
should  not  be  as  high  nor  the  bating  as  low  as  for  heavy  upper 
leather. 

Harness  hides  should  be  thoroughly  cleansed  from  lime  be- 
fore they  are  sent  to  the  tan  yard ;  this  may  be  easily  accom- 
plished without  the  use  of  deteriorating  excreta  or  extracting 
the  gelatine,  but  so  swelling  the  fibrine  that  it  will  receive  the 
tannic  acid,  and  blend  readily  and  perfectly,  giving  firmness 
without  destroying  the  elasticity  or  causing  a  tendency  in  the 
grain  to  crack  when  in  use  as  harness,  etc. 

It  is  absolutely  necessary  that  a  thoroughly  serviceable 
leather,  which  ensures  the  desired  softness  and  pliability,  and 
at  the  same  time  is  free  from  a  tendency  to  crack  or  get  hard 
in  use,  should  be  used  in  harness  making.  Harness  leather 
must  be  a  great  deal  more  flexible  than  either  sole  or  heavy 
belt  leather,  and  must  have  as  high  a  degree  of  tensile  strength 
as  can  be  retained  in  the  course  of  manufacture,  while  its  sur- 
face must  be  fine  and  such  as  will  readily  take  a  variety  of  kinds 
and  styles  of  finish.  Lighter  hides  are,  therefore,  used  more 
generally  than  heavier  ones,  yet,  even  then,  there  is  no  effort 
made  to  combine  with  the  gelatinous  body  in  the  hide-cells  as 
large  an  amount  of  tannins  as  the  latter  will  take.  A  more 
thorough  working  over  of  the  surface  then  becomes  necessary, 
and  a  very  considerable  amount  of  dressing  or  stuffing  of  tal- 
low and  grease  is,  therefore,  worked  into  it,  while  this,  what- 

(  39°  ) 


HARNESS  AND  BELTING  LEATHER. 


391 


ever  the  coloring  may  be,  will  bring  the  product,  in  many 
cases,  very  nearly  to  the  substance  of  a  leather  generally  used 
for  the  uppers  of  boots  and  shoes.  As  we  get  to  the  lighter 
leather  used  for  harness  purposes,  upper  leather  for  boots  and 
shoes,  and  for  goods  of  a  miscellaneous  character,  the  tanning 
proper,  although  always  a  matter  of  very  great  importance, 
loses  here  some  of  its  former  purpose,  and  the  work  of  the 
currier  and  finisher  then  becomes  a  prime  essential  in  the  man- 
ufacture. 

It  is  perfectly  proper  that  the  skins  and  lighter  hides  used  to 
manufacture  these  proportionately  light  goods  should  not  con- 
tain as  much  gelatinous  matter  in  their  cellular  tissues  as  would 
the  thicker  and,  consequently,  heavier  ones  chosen  for  the  tan- 
nage of  sole  leather ;  and  they,  besides,  are  not  treated  with 
tanning  liquors  of  the  same  concentration  as  would  be  required 
for  such  heavy  goods. 

If  too  concentrated  solutions  of  tannins  are  used  for  skins 
and  lighter  hides,  the  natural  consequence  will  be  that  the  pro- 
ducts of  such  a  tannage  are  substances  altogether  the  opposite 
of  what  we  require  for  saddlery  and  harness  manufacturing  pur- 
poses ;  flexibility  and  tensile  strength  would  be  lacking.  It 
must  be  admitted  that  the  kinds  of  the  lighter  goods  in  the 
market  are  much  more  numerous  than  are  those  used  for  soles 
and  for  heavy  belting,  and  their  qualities  vary  more  widely, 
but  by  far  the  larger  proportion  of  the  goods  made  for  such 
use — from  the  skins  of  calves  and  partially  grown  cattle,  as 
well  as  those  from  larger  hides  in  split  form — are  tanned  with 
the  same  tanning  materials  as  are  used  in  manufacturing  certain 
heavier  leather. 

It  will  not  be  inappropriate  here  to  make  a  few  remarks  on 
belting  for  lighter  purposes,  as  this  is  analogous  to  certain 
parts  of  harness ;  and  it  must  be  remarked  that,  as  it  should 
have  greater  flexibility  than  is  found  in  heavy  sole  leather,  the 
tanner  must  avoid  filling  the  cells  of  the  hides  too  thoroughly 
with  tannins.  If  these  rules  are  not  observed,  the  natural  posi- 
tion of  the  fibrous  parts  of  hides  may  be  disturbed. 


392 


THE  MANUFACTURE  OF  LEATHER. 


It  must  be  remembered  that  these  fibrous  bodies  give  the 
whole  structural  substance  its  tensile  strength,  although  the 
fact  may  be  acknowledged  in  a  general  sense  only.  For  one 
thing,  it  is  correct  in  theory,  and  it  must  also  have  some 
bearing  on  practice ;  and  it  is  certain  that  it  insures  to  the 
lighter  kinds  the  same  tannage,  providing  the  varying  precau- 
tions necessary  are  duly  observed.  The  distinction  between 
different  kinds,  so  far  as  this  rests  in  the  substance  of  the 
texture  itself,  may  be  more  theoretical  than  practical  when 
viewed  in  regard  to  the  common  usages  of  the  trade,  but  cer- 
tain important  distinctive  properties  traceable  cannot  be  dis- 
puted. 

All  the  large  hides  and  sides  of  patent  and  enameled  leather 
for  harness  and  carriages  are  split  goods,  and  are  generally  of 
the  largest  spread  that  can  be  obtained.  Three  splits  are  fre- 
quently made,  the  first  being  taken  from  the  flesh  side,  and 
termed  "junior."  The  small  splits  are  usually  deficient  in 
strength,  and  cannot  therefore  be  recommended  for  purposes 
where  a  fair  amount  of  tensile  strength  is  requisite,  or  where 
general  safety  is  placed  at  stake  through  their  use. 

Chrome  tannage  is  now  being  introduced  for  the  tanning  of 
both  harness  and  belting  leather,  and  it  makes  a  strong,  tough 
fabric. 

An  extract  company  of  West  Virginia  are  the  owners  of  a 
quick  tanning  process  by  which  they  claim  to  be  tanning  No.  1 
harness  leather  in  40  days  and  the  best  oak  sole  in  60  days  by 
the  use  of  their  process  and  their  refined  chestnut  oak  bark  ex- 
tract. They  have  practically  demonstrated  to  many  tanners 
that,  with  the  proper  use  of  refined  chestnut  oak  bark  extract 
and  the  new  method  of  handling  their  hides,  the  cost  of  their 
tannage  is  reduced  from  15  to  25  per  cent. 

CURRYING  HARNESS  LEATHER. 

Harness  hides  and  backs,  after  soaking,  should  be  shaved 
over  with  care,  only  taking  off  the  flesh,  so  as  to  leave  a 
smooth,  even  surface.    They  should  then  be  well  scoured  on 


HARNESS  AND  BELTING  LEATHER. 


393 


flesh  and  grain  out  of  liberal  baths  of  tolerably  warm  water, 
which  opens  them  and  allows  them  to  be  better  extended  and 
slicked  out  as  firm  and  free  from  water  as  possible ;  they  are 
then  ready  for  the  shed.  They  require  to  be  well  set,  keeping 
the  straight  edge  in  a  line  with  the  front  edge  of  the  table. 
Two  men  are  generally  employed  at  this  work,  and  each  should 
stone  so  that  they  cross  each  stroke,  laying  the  goods  out  per- 
fectly flat  and  firm,  and  then  with  a  thick  steel  slicker  take  out 
all  the  stone  and  other  marks ;  then  oil  them  on  the  grain 
with  good  oil  and  turn  over  for  stuffing  on  the  flesh,  which 
must  be  done  without  folding  or  creasing  the  hide  or  causing 
any  contractions.  Hides  dressed  in  full  length  should  have  a 
loop  at  each  end  and  one  near  the  centre  of  the  backs  to  pre- 
vent their  drying  baggy.  When  nearly  dry  they  require  re- 
setting, the  parts  that  are  too  dry  being  damped  so  that  the  hide 
or  back  is  equally  moist  all  over,  and  by  keeping  the  table  wet 
before  each  side  is  set  it  will  prevent  unnecessary  removal  of 
grease  from  the  flesh.  Scarcely  too  much  labor  can  be  be- 
stowed here,  as  it  should  be  the  consolidation  of  the  pattern  pre- 
pared in  previous  stages.  The  grain  should  be  carefully 
slicked  again,  so  that  no  tool  marks  are  left,  and  when  dried 
out  the  sides  are  ready  for  blacking,  which  by  some  is  done  by 
brushing  them  over  with  urine  and  soda  or  fuller's  earth,  but 
we  prefer  very  hot  refuse  sumac  liquor  and  fuller's  earth,  as  it 
requires  less  wetting  and  is  cleaner.  Every  grease  spot  should 
be  removed  or  it  will  not  receive  the  dye,  and  be  the  cause  of 
much  extra  labor  when  it  cannot  so  well  be  done.  They  will 
now  require  the  final  setting,  which  will  be  but  very  slight  if  it 
has  been  properly  done  in  scouring  and  stuffing.  Care  is 
again  required  here  to  leave  no  tool  marks,  and  to  facilitate  a 
good  grain  surface  a  heavy  glass  slicker  should  be  used.  They 
should  then  have  a  good  dressing  of  tallow  dubbin  on  the  grain 
and  finished  drying,  when  they  may  be  laid  down  for  stock  or 
the  grease  slicked  off,  and  have  a  last  dressing  of  hot  tallow  on 
the  grain.  This  gives  a  polished  surface  after  laying  a  short  time. 
The  same   process  will   be   sufficient   for   brown  harness 


394 


THE  MANUFACTURE  OF  LEATHER. 


leather,  leaving  out  the  part  for  blacking,  and  where  the  color 
is  required  to  be  bright  a  good  sumacing  will  greatly  help  it, 
and  the  stuffing  can  be  adapted  accordingly. 

Bridle  butts,  bellies  and  shoulders,  after  soaking,  should  be 
shaved  clean,  all  the  flesh  being  taken  off,  then  well  set  out  on 
the  table  with  stone  and  slicker,  so  as  to  fully  extend  them  and 
get  out  all  contractions,  then  be  again  shaved  to  the  required  level 
substance.  When  they  are  ready  for  scouring,  some  curriers 
object  to  warm  water,  but  it  is  very  necessary  for  these  goods, 
as  it  not  only  aids  in  cleansing,  but  it  opens  or  rather  mellows 
the  fibres  so  that  the  leather  may  be  fully  extended  and  laid 
flat;  they  should  then  be  placed  in  a  tub  or  vat,  with  sufficient 
warm  water  to  cover  them  without  pressure,  and  be  firmly 
slicked  out  on  the  flesh  and  well  brushed  over  and  put  back 
into  rather  warmer  water  than  before,  but  not  hotter  than  the 
hand  can  be  held  in,  as  heat  in  this  state  of  leather  that  will  not 
injure  the  flesh  of  the  operator  will  not  injure  the  article  ope- 
rated on.  They  must  now  be  well  scoured  on  the  grain.  A  stone 
slicker  is  the  best  for  this  part,  if  not  too  coarse,  and  after  an 
extra  good  brushing  be  put  again  into  clean  warm  water  and 
sleaked  out  tight  on  the  grain  for  compoing.  We  give  this 
rather  fully,  as  color  depends  so  much  upon  how  this  part  is 
done,  and  cannot  be  remedied  if  neglected.  They  should  now 
have  a  good  sumacing,  each  one  being  dipped  separately  and 
quickly  while  the  liquor  is  hot;  and  when  all  are  done,  stir  the 
liquor  up  well,  as  the  bottom  holds  the  heat  and  would  burn  the 
goods  that  came  in  contact  with  it,  though  the  surrounding 
liquor  is  cool;  and  when  it  is  well  settled  put  them  in  one  at  a 
time,  having  sufficient  liquor  that  they  are  not  pressed,  and 
pull  them  out  next  day;  let  them  lay  an  hour  and  lay  them  in 
as  before,  and  the  next  day  they  will  be  ready  to  slick  out 
again,  which  should  be  thoroughly  done.  They  may  now  be 
hung  in  shed  for  a  short  time,  only  sufficient  to  absorb  the 
moisture  that  would  slick  out  on  the  table  and  not  approach 
to  stiffness  or  dry  in  any  part,  then  set  them  out  on  the  grain 
firmly,  keeping  the  edge  of  the  butts  (where  cut  down  the 


HARNESS  AND  BELTING  LEATHER. 


395 


back)  in  a  straight  line  with  the  table,  and  leaving  no  tool 
marks  in.  Give  them  a  thin  dressing  of  good  tallow,  dubbin 
and  turn  over;  lay  them  flat  with  a  thin  slicker  very  lightly, 
stuff  them  with  dubbin  made  with  the  best  cod  oil  and  pure 
tallow,  as  stiff  with  tallow  as  it  can  be  spread,  as  its  properties 
are  the  most  value  in  these  goods,  producing  mellowness, 
brightness  of  color,  and  facilitating  a  glossy  finish.  When  they 
are  about  half  dry  they  should  be  lightly  set  and  hung  up  to 
finish  drying,  and  may  be  sleaked  off  and  glossed  when  re- 
quired, but  will  improve  by  laying  a  few  weeks  before  finishing. 

The  old-fashioned  oak  bark  tannage  is  still  used  for  harness 
leather ;  the  best  leather  is  from  Chicago  packer  native  steer 
hides,  which  make  a  tough  and  durable  leather  ;  they  are  clean 
shaved  all  over  and  stuffed  with  pure  oil  and  tallow,  carefully 
trimmed  and  closely  selected. 

Curriers'  Skirting — This  is  for  finishing  skirting  and  the  flesh 
of  harness  leather  in  imitation  of  oak  tanning.  Take  of  chrome 
yellow,  y2  lb. ;  yellow  ochre,  I  lb. ;  cream  of  tartar,  I  oz. ; 
soda,  ]/2  oz. ;  paste,  5  quarts ;  mix  well.  This  will  finish 
twelve  sides. 

GERMAN  HARNESS  LEATHER. 

Green  hides,  if  possible,  are  used  for  these  varieties.  As 
many  hides  as  can  be  placed  in  the  lime  pit  are,  after  cutting 
out  the  horns,  soaked  in  running  water  six  to  eight  hours  with 
frequent  rinsing,  next  cleansed  from  dung  and  placed  in  weak 
milk  of  lime  for  twenty-four  hours.  They  are  then  taken  out  and 
replaced,  after  preparing  fresh  lime  for  twenty-four  hours  more, 
when  they  are  again  handled.  After  this  they  are  regularly 
handled.  Depilation  is  effected  as  soon  as  the  hair  can  be 
easily  pulled  out,  after  which  the  hides  are  soaked  in  water  for 
a  few  hours.  Water  stripes  and  dots  are  produced  by  soaking 
the  hides  too  long  in  running  water  and  allowing  them  to  re- 
main stationary.  After  fleshing  and  soaking  for  twenty-four 
hours  the  hides  are  smoothed  and  placed  in  the  bate  for  one  to 
three  days,  according  to  their  thickness  and  the  state  of  the 


396 


THE  MANUFACTURE  OF  LEATHER. 


weather.  They  are  handled  three  times  every  day  they  remain 
in  the  bate.  If  the  England  wheel  is  employed,  the  bating  can 
be  accomplished  in  from  eight  to  ten  hours.  Special  attention 
should  be  paid  to  this  process,  as  soft  leather  can  only  be  pro- 
duced by  proper  bating,  while  too  much  bating  is  injurious,  as 
it  destroys  the  skin  fibres  and  the  grain.  After  taking  the 
hides  from  the  bate  and  rinsing  in  fresh  water  they  are  again 
smoothed,  and  after  soaking  for  several  hours  thoroughly 
worked  upon  the  flesh  side  with  a  dull  fleshing-knife.  They  are 
then  ready  for  tanning. 

Salted  hides  of  cows  and  oxen  are  soaked  three  days,  special 
attention  being  paid  to  removing  all  the  salt  before  placing  the 
hides  in  the  lime  pit.  Dried  hides,  after  thoroughly  soaking 
and  bringing  them  back  to  their  original  shape  by  stretching, 
are  treated  in  the  same  manner  as  green  hides.  By  using  the 
hide  mill  much  labor  in  stretching  and  smoothing  may  be 
saved,  and  for  inferior  hides  slicking  also. 

The  handling  vats  should  be  sufficiently  large  to  allow  of  the 
convenient  handling  of  the  hides. 

It  is  generally  preferred  to  place  the  leather  in  old  liquor  for 
one  or  two  days,  according  to  the  quality  of  the  liquor  in  the 
vat.  The  leathers  are  taken  out  and  replaced  and  treated  in 
the  same  manner  as  above,  after  ladling  out  the  old  tan  and 
adding  one-third  bushel  of  fresh  tan.  According  to  the  state 
of  the  weather  the  power  of  the  tan  will  be  exhausted  in  four 
to  eight  days,  it  then  becoming  necessary  to  freshen  the  vats. 
After  doing  this  twice  or  three  times  more  the  leathers  are 
placed  in  the  lay-aways,  where  they  remain  for  about  the  same 
period  as  for  sole  leather,  a  longer  period  being,  as  a  general 
rule,  only  required  for  stout  harness  and  vache-leather,  but  it  is 
absolutely  necessary  for  belt  leather. 

In  order  to  see  how  far  tanning  has  proceeded,  it  is  advisable 
to  split  the  leather  after  the  second  layer.  The  cut  of  a  thor- 
oughly tanned  hide  will  be  uniformly  brown,  while  a  pale  yel- 
low or  white  coloring  is  a  proof  of  insufficient  tanning. 

After  splitting  the  hides  into  sides  and  numbering  the  two 


HARNESS  AND  HKLTING  LEATHER. 


397 


halves  with  the  same  number,  the  completely  tanned  leather  is 
rinsed  in  old  ooze  and  smoothed  with  a  dull  fleshing  knife 
upon  the  beam.  Where  all  three  kinds  of  leather  arc  made, 
the  best  hides  arc  used  for  harness  leather,  the  strongest  for 
belt  leather  and  the  poorest  for  vache  leather. 

The  harness  leather  is  gone  over  with  a  fine-edged  knife  and 
then  greased  upon  the  flesh  side  with  a  mixture  of  linseed  oil 
and  tallow  and  hung  up  to  dry.  Vache  leather  is  also  greased, 
but  only  slightly,  upon  the  grain  side,  and  then  dried. 

PREPARATION  OF  VACHE  LEATHER. 

The  dry  hides  are  soaked  in  sufficient  well  water  to  cover 
them  in  a  vat,  handled  after  an  hour,  then  replaced  and  allowed 
to  soak  over  night.  The  next  day  they  are  placed  upon  a 
wooden  table,  and  after  tucking  in  the  shanks  rolled  up,  grain 
side  in,  from  the  head  to  the  tail,  so  that  every  half  hide  forms 
a  roll.  The  rolls  are  tied  together  with  strong  twine  or  leather 
straps,  so  that  they  will  not  become  unrolled  in  the  succeeding 
beating  with  fluted  wooden  mallets,  which  is  continued  until 
the  hide  feels  soft  to  the  touch. 

To  soften  the  hides  completely  the)'  are  boarded,  after  beat- 
ing, upon  the  grain  side  with  a  coarse  graining  board.  After 
working  ten  or  twelve  hides  in  this  manner,  a  thin  shaving  is 
taken  from  the  flesh  side.  The  best  plan  is  to  have  two  work- 
men perform  the  above  operations,  and  also  the  succeeding 
ones.  In  tanneries  provided  with  a  fulling  mill,  a  higher  de- 
gree of  suppleness  can  be  imparted  to  vache  hides  by  fulling 
than  is  possible  by  beating  and  boarding  with  the  graining 
board. 

One-half  of  the  hide  is  then  placed  upon  a  somewhat  in- 
clined table  of  wood,  slate  or  glass  as  long  as  the  hide  and  as 
wide  as  one-half  the  hide,  and  scrubbed  with  brushes  con- 
stantly dipped  in  water  until  the  flesh  side  acquires  a  mushy 
condition,  which  can  be  recognized  by  the  impressions  made 
by  passing  the  fingers  over  the  hide  remaining  visible.  It  is 
then  turned  over,  and,  after  placing  the  back  part  in  a  straight 


398 


THE  MANUFACTURE  OF  LEATHER. 


line  with  the  edge  of  the  table  and  passing  the  hand  over  the 
hide  so  that  it  sticks  to  the  table,  the  grain  side  is  treated  in 
the  same  manner. 

The  slicker  is  then  driven  first  along  the  back  to  prevent  the 
wrinkles  which  are  formed  from  sticking  and  then  in  the  direc- 
tion from  the  back  to  the  foreshank.  After  removing  the 
wrinkles,  which  is  absolutely  necessary,  more  force  may  be 
used  for  the  removal  of  tan  depressions. 

As  soon  as  one-half  of  the  hide  is  slickered  it  is  immediately 
hung  up  in  the  drying  loft.  If  this  is  higher  than  the  length 
of  the  hide,  the  latter  is  nailed  through  the  hind  shank  and  root 
of  the  tail  to  short  strong  sticks,  or  incisions  are  made  in  these 
places,  and  after  passing  through  the  sticks  the  latter  are  placed 
between  two  poles. 

If  the  loft  is  not  very  high,  the  back  part  of  the  hide  is  nailed 
to  straight,  strong  poles,  which  after  tying  the  front  and  hind 
shanks  with  twine  in  such  a  manner  that  they  cannot  hang  down 
and  form  wrinkles,  are  placed  in  the  pole  rack. 

After  the  hides  are  partly  dry,  they  are  placed  separately 
upon  the  table,  and,  after  wetting  slightly  such  parts  as  have 
become  too  dry,  one  hide  is  placed  above  the  other  and  the 
pile  repacked.  The  hides,  moistened  first,  are  then  replaced 
upon  the  table,  and  after  fitting  the  back  exactly  to  the  edge 
of  the  table  it  is  fastened  with  a  few  wooden  clamps,  the  im- 
pressions of  which  are  removed  later  on. 

To  remove  all  tan  depressions  and  to  give  the  leather  a 
beautiful  appearance  and  firm  touch,  the  use  of  a  roller  is  of 
great  advantage,  especially  as  it  facilitates  the  currying  and 
prevents  the  grain  from  being  injured  by  constant  working. 

The  tan  impressions,  etc.,  are  then  entirely  removed,  and 
after  rubbing  with  a  moist  woolen  rag,  the  sides  are  stamped 
and  hung  up. 

Before  the  hides  become  entirely  dry  the  halves  are  fitted 
together  according  to  the  numbers,  and  placed  grain  side  upon 
grain  side  and  hide  upon  hide  until  a  pile  is  formed,  which  is 
covered  with  planks  somewhat  loaded. 


HARNESS  AND  BELTING  LEATHER. 


399 


After  remaining  here  for  twelve  hours  they  are  hung  across 
poles  and  gradually  dried.  Each  hide  is  then  rolled  up  sepa- 
rately and  about  six  placed  in  one  bundle,  which  is  secured 
with  twine. 

It  is  scarcely  necessary  to  say  that  scrupulous  cleanliness 
must  prevail  during  all  these  operations.  By  strictly  following 
the  directions  given,  an  article  fulfilling  all  demands  will  be  the 
result,  and  one  which  is  not  only  equal  to  the  best  Frankfurt 
vache  leather,  but  in  most  cases  surpasses  it  as  regards  beauty 
and  quality. 

After  the  harness  leather  has  passed  through  all  the  above 
operations,  it  is  sorted  into  brown  and  black.  The  first  ac- 
quires lustre  by  means  of  a  glassing  machine  or  is  sold  without 
it.  The  black  leather,  after  grounding  with  decoction  of  log- 
wood, is  blacked  with  iron  black  and,  when  nearly  dry,  passed 
through  the  press. 

The  best  qualities  of  light  hides  from  Buenos  Ayres,  Monte- 
video and  Texas  may  also  be  used  for  vache  leather.  The 
lime  used  for  hides  intended  for  vache  leather  and  inside  sole 
leather,  is  sometimes  mixed  with  red  arsenic.  This  has  a 
better  effect  upon  the  hide,  also  softening  hard  places  found  in 
these  hides,  which  are  always  difficult  to  soften.  In  using  this 
mixture  the  hides  require  more  frequent  handling  than  in  the 
ordinary  liming  process,  and  should  be  depilated  as  soon  as 
possible.  As  the  hides  are  not  raised  by  the  mixture,  it  may 
also  be  recommended  to  subject  them  to  the  ordinary  liming 
for  a  day,  after  taking  them  from  the  arsenic  and  lime  liquor. 
This  method  of  liming  can  also  be  advantageously  employed  in 
preparing  green  hides  and  kips  for  upper  leather,  but  the  after 
liming  must  be  contiuued  for  a  correspondingly  longer  time. 

DRUM  TANNAGE. 

Drum  tanning  for  harness,  strap  leather,  etc.,  is  growing 
steadily  in  favor.  If  properly  conducted,  drum  tannage  pro- 
duces leather  fully  equal  to  that  produced  by  older  methods, 
both  as  regards  quality  and  appearance.  There  is  no  doubt  that 


THE  MANUFACTURE  OF  LEATHER. 


this  mode  of  tanning  would  be  far  more  generally  practiced 
than  is  actually  the  case,  were  it  not  for  the  heavy  royalties 
exacted  by  the  owners  of  the  patents  and  for  the  fact  that 
a  powerful  motive  and  mechanical  equipment,  available  in 
very  few  tanneries,  is  required.  Tanneries  constructed  in 
future  specially  for  making  these  kinds  of  leather  will,  how- 
ever, henceforth  doubtless  have  to  be  planned  with  a  view  to 
drum-tanning.  . 

INDIAN  HARNESS  LEATHER. 

In  an  article  by  Walter  G.  McMillan,  read  before  the  Society 
of  Chemical  Industry,  the  author  stated  that  the  Director  Gen- 
eral of  Ordnance  in  India  asked  him  to  undertake  a  series  of 
mechanical  tests  with  the  object  of  ascertaining  the  tensile 
strength  of  harness  leather  made  in  the  Government  Harness 
and  Saddlery  Factory  at  Cawnpur,  and  to  compare  it  with 
that  of  samples  made  in  private  tanneries  in  Madras  and  in 
England.  Several  hundred  tests  of  various  kinds  were  made, 
and  it  is  proposed,  with  the  sanction  of  General  Walker,  to 
summarize  the  more  useful  of  these  results  in  this  short 
paper.  Visits  to  the  Cawnpur  factory  have  enabled  the  writer 
to  give  a  sketch  of  the  system  of  tannage  by  which  the 
leather  was  made,  and  thus  to  give  additional  interest  to  the 
research. 

The  factory  is  worked  by  the  Ordnance  Department  of 
India,  under  the  immediate  superintendence  of  officers  of  the 
Royal  Artillery.  The  foreman  is  an  experienced  English 
tanner,  and  he  is  assisted  by  several  staff  sergeants  instructed 
by  him  in  such  details  as  are  required  to  enable  them  to 
supervise  the  native  workmen  in  their  own  departments.  The 
tannery  is  of  no  mean  size,  there  being  usually  from  35,000  to 
40,000  hides  under  treatment  in  the  tanyard  at  a  time.  The 
currying  and  the  subsequent  fashioning  of  the  leather  into 
harness  and  saddlery  components  are  conducted  in  the  same 
establishment. 


HARNESS  AND  BELTING  LEATHER. 


40I 


THE  SYSTEM  OF  TANNAGE  USED  IN  THE  CAWNPUR  FACTORY. 

The  factory  is  situated  on  the  banks  of  the  Ganges,  close  to 
the  point  at  which  it  is  joined  by  the  Ganges  Canal,  and  it  is 
from  this  latter  source  that  the  water  supply  is  drawn.  The 
following  numbers  are  the  results  of  an  analysis  of  water  from 
this  canal  made  by  Dr.  Compigne  in  the  autumn  of  1867,  and 
recorded  in  a  Government  publication  : 


Degree  of  total  hardness  4.7 

Degree  of  permanent  hardness  2.8 

Solids  in  70,000  grains  of  filtered  water  8.26 

Mineral  matters  7.56 

Earthy  salts,  etc.,  insoluble  in  water  5.07 

Lime  as  carbonate  2.6 

Soluble  salts  2.5 

Sodium  chloride  1.5 


With  the  exception  of  the  somewhat  large  percentage  of 
suspended  matter — a  difficulty  met  by  allowing  the  supply  to 
stand  in  settling  tanks  before  use — the  water  appears  to  be 
suited  for  the  work  of  the  place. 

The  hides  are  for  the  most  part  buffalo  and  cow  hides, 
which  come  to  the  factory  from  different  parts  of  India  very 
lightly  salted,  while  a  few  are  obtained  green  from  the  Cawnpur 
butchers  and  require  immediate  treatment.  They  are  said  to 
be  fairly  well  flayed  as  a  rule,  with  but  few  flesh  cuts  and  little 
fat.  Occasionally,  careless  handling  prior  to  salting  is  found 
to  have  produced  local  putrefaction,  which  greatly  deteriorates 
or  destroys  the  skin,  and  is  made  apparent  in  the  lime  pits, 
even  if  it  had  not  declared  itself  previously. 

The  tanning  material  used  has  generally  been  Babul  (Acacia 
Arabica)  bark,  with  a  small  proportion  of  myrobolans  ;  within 
the  last  few  months  valonia  has  been  substituted  for  the  latter, 
but  all  the  Cawnpur  leather  referred  to  in  this  paper  was  made 
with  the  addition  of  myrobolans.  A  few  experiments  were 
tried  with  a  view  to  introducing  the  use  of  Sal  (Shorea  Ro- 
busta)  bark  in  place  of  Babul,  but  the  leather  so  prepared  was 
somewhat  hard  and  dark  colored,  and  gave  a  distinctly  inferior 
26 


402 


THE  MANUFACTURE  OF  LEATHER. 


test,  as  the  numbers  quoted  hereafter  will  show.  Babul  bark, 
which  is  abundantly  obtainable  from  local  contractors,  has  been 
found  by  Christy  to  yield  18.95  Per  cent,  of  a  good  cream- 
colored  tannin.  A  sample  given  to  the  author  on  the  occasion 
of  his  visit  to  Cawnpur  in  1893,  gave  21  per  cent,  of  tannin, 
while  a  specimen  of  Sal  bark  yielded  only  9  per  cent.  The 
bark  is  said  to  be  of  fairly  constant  strength,  showing  only  a 
slight  loss  of  tannin  (by  exposure)  during  the  rainy  season. 
The  exhaustion  of  the  bark  is  effected  in  latches,  which  are 
worked  in  series  of  eight,  giving  different  solutions,  with  a 
range  of  from  2  to  50  degrees  barkometer.  The  latches  are  of 
brick,  with  wooden  false  bottoms,  and  are  of  three  different 
sizes  in  different  sheds.  The  sizes  and  weights  of  material 
employed  are  as  follows : 

Charge  of 
Charge  of  Bark.  Myrobolans. 
Size  of  Latch.  Cwt.  Cwt. 

12x10x8    50  15 

10x10x8    50  15 

1 0x9x8 1£    35  10 

The  tan  liquors  are  returned  to  be  refreshed  to  one  or  other  , 
of  the  latches,  according  to  the  strength  indicated. 

The  tanning  process  is  conducted  as  follows : 

The  hides  are  soaked  in  pits  in  which  the  water  is  changed 
whenever,  from  its  appearance,  it  is  judged  to  require  renewal. 
They  are  then  stocked  for  about  half  an  hour  in  a  gentle  stream 
of  running  water. 

They  are  next  limed  in  a  series  of  six  pits,  each  fresher  than 
the  last.  The  lime  pits  are,  as  usual,  worked  in  a  rotation, 
being  made  up  originally  with  5  cwt.  of  lime  to  the  pit;  this 
liquor  lasts  for  about  a  month  without  further  addition  of  lime, 
and  treats  700  or  800  hides.  Each  hide  may  remain  in  the 
lime  for  from  15  to  18  days,  but  in  the  hottest  weather  a  some- 
what shorter  soaking  suffices. 

They  are  now  unhaired  and  fleshed,  and  are  then  bated  in  a 
liquor  made  up  by  extracting  seeds  from  the  pods  of  the  babul 


HARNESS  AND  BELTING  LEATHER. 


403 


tree  with  water.  This  bate  has  originally  about  2  cwt.  of  the 
seed  to  each  pit,  and  lasts  about  three  weeks ;  a  gentle  fermen- 
tation is  initially  set  up  by  the  addition  of  a  few  buckets  of  tan 
liquor.  For  light  leather  a  bran  bate  is  generally  substituted. 
The  process  demands  careful  attention  at  all  times,  but  par- 
ticularly in  the  hot  season. 

The  hides  are  now  at  once  transferred  to  handlers  containing 
weak  liquors  (7  to  8  degrees)  for  two  or  three  days,  being 
handled  every  two  or  three  hours  during  the  first  day.  The 
spent  liquors  from  this  vat  are  allowed  to  run  to  waste.  After 
this  the  skins  are  handled  daily  for  about  a  month  in  stronger 
liquor  (15  degrees),  then  for  a  month  in  "floaters"  in  liquor 
of  about  20  degrees;  next  they  are  transferred  to  "dusters," 
working  at  a  strength  of  30  degrees  and  containing  a  small 
proportion  of  fresh  bark ;  here  they  are  handled  daily  for  from 
one  to  two  months,  and  are  then  put  away  for  about  six  months 
in  layers,  the  liquor  strength  in  which  varies  from  35  to  50  de- 
grees, but  averages  45  degrees.  Each  layer  pit  contains,  in 
addition  to  the  liquor,  4  cwt.  of  bark  and  2  cwt.  of  myrobolans, 
and  treats  100  hides. 

CURRYING. 

The  hides  are  now  transferred  to  the  curriers'  shops,  where 
they  are  successively  shaved  to  the  required  thickness,  scoured 
on  flesh  and  grain,  passed  rapidly  through  weak  sumac  liquors, 
oiled  with  cod  oil,  sammied  and  struck  out,  reshaved  or  flatted, 
stuffed  with  a  mixture  of  cod  oil  and  tallow  (in  equal  parts  in 
the  cold  season,  but  containing  60  per  cent,  of  tallow  in  the  hot 
season)  and  are  finally  dried  out  and  finished  by  the  removal 
of  surplus  grease. 

In  all  the  processes  here  described  the  average  treatment 
has  been  given,  but  this  must  of  necessity  be  greatly  modified 
at  different  seasons  in  a  climate  which  is  equivalent  to  an  Eng- 
lish summer  in  the  cold  weather,  where  the  thermometer  may 
daily  rise  for  several  months  to  over  ioo°  F.,  when  a  very 
small  proportion  of  atmospheric  moisture  exists,  and  where  for 


404 


THE  MANUFACTURE  OF  LEATHER. 


two  or  three  months  the  atmosphere  may  be  saturated  with 
water  vapor  with  a  thermometer  indication  of  over  90  degrees. 

Concerning  the  processes  used  in  the  preparation  of  the 
Madras  and  of  the  English  leather,  the  author  has  no  informa- 
tion. The  latter  leather,  however,  was  taken  from  a  large  num- 
ber of  hides  supplied  to  the  Government  by  a  good  firm  of 
English  tanners. 

The  tests  to  be  described  were  made  chiefly  with  new  leather. 
Half  hides  were  supplied  to  the  author's  department  and  were 
cut,  under  his  direction,  in  the  manner  detailed  below.  A  cer- 
tain number  of  the  Cawnpur  (Babul  and  Sal-tanned)  English 
hides  were  made  up  at  Cawnpur  into  harness  components, 
were  issued  to  a  battery  of  artillery,  and,  after  six  months'  ser- 
vice, were  returned  for  test,  and  were  then  cut  up  into  straps 
of  suitable  shape  and  size  for  the  testing  machine.  The  testing 
machine  was  one  of  Greenwood  and  Batley's  lever  pattern,  and 
although  intended  and  generally  used  to  test  metallic  speci- 
mens up  to  a  100-ton  load,  was  yet  equally  well  adapted  to  the 
measurement  of  any  stress  exceeding  500  pounds. 

TESTS  OF  NEW  LEATHER. 

The  half  skins  being  submitted,  straps  measuring  in  the  test 
portion  10  inches  in  length  by  2  inches  in  width,  were  cut 
from  different  positions  in  the  hide. 

The  results  of  the  tests  were  that  the  Cawnpur  hides,  as  com- 
pared with  English  and  Madras  hides,  both  heavy  and  light, 
showed  8  to  10  per  cent,  greater  strength  at  the  average  break- 
ing stress  and  less  stretch.  The  English  hides  showed  greater 
resistance  when  wet  than  either  the  Cawnpur  or  Madras.  The 
most  absorbent  and  least  dense  leather  in  regard  to  water  was 
the  Cawnpur,  next  the  Madras,  and  last  the  English.  It  was 
found  that  the  narrower  straps  were  proportionately  stronger 
than  a  wide  one,  and  that  the  weakening  of  a  strap  produced 
by  the  perforations  to  receive  the  tang  of  the  buckles  was 
nearly  one-half. 

Finally,  to  bring  to  a  focus  a  few  of  the  points  which  appear 
to  be  indicated  by  the  experiments  quoted  in  the  paper: 


HARNESS  AND  BELTING  LEATHER. 


A.  In  comparing  the  leathers  produced  by  the  two  systems 
of  tannage,  that  which  had  the  lower  specific  gravity  ( wet  or 
dry)  was  to  a  marked  extent  more  absorbent  than  the  other, 
and  was  at  the  same  time  stronger  both  actually  and  per  square 
inch  of  section,  but  stretched  less  before  rupture. 

B.  In  leather  produced  by  a  green  system  of  tannage. 

1.  Thin  hides  are  stronger  per  unit  of  sectional  area  than 
thick  hides,  while  the  ultimate  extension  before  rupture,  al- 
though practically  the  same,  is  on  the  average  slightly  greater 
in  the  stouter  specimens. 

2.  Thin  hides  are  more  absorbent  and  have  a  lower  specific 
gravity  when  wet  than  thick  hides. 

3.  In  any  given  hide,  omitting  from  consideration  the  ex- 
treme neck  portion  of  the  back,  which  is  altogether  inferior, 
straps  from  the  rump  half  should  carry  a  higher  actual  load  by 
reason  of  their  greater  thickness,  but  will  nevertheless  stand  a 
lower  stress  per  square  inch  than  those  from  the  neck  half. 

4.  With  average  hides,  a  comparison  of  strength  per  unit  of 
sectional  area  is  permissible,  but  shaving  or  an  exceptionally 
severe  use  of  the  fleshing  knife  may  lower  the  strength  per 
square  inch  of  section,  while  it  increases  the  extensibility. 

5.  Other  things  being  equal,  a  narrow  strap  may  be  ex- 
pected to  be  not  only  stronger  than  a  wide  one,  both  actually 
and  per  unit  of  sectional  area,  but  also  to  stretch  more  under 
a  given  load. 

MACHINE  BELT  LEATHER  GREASED  WITH  TALLOW. 

By  greasing  with  tallow  this  leather  acquires  the  desirable 
property  of  not  becoming  hard,  even  if  the  belt  cut  from  it  has 
to  pass,  as  is  frequently  the  case,  through  water.  This  leather 
is  tanned  in  the  same  manner  as  has  been  described  for  sole 
leather,  complete  tanning  being  the  principal  requisite. 

After  dividing  the  hides  into  sides  and  rinsing  off  the  tan,  the 
sides  are  scoured  either  by  hand  or  machinery,  so  as  to  pre- 
pare them  for  the  reception  of  the  tallow.  The  sides  are  then 
treated  differently  from  the  leather  that  is  to  be  used  for  uppers 


406 


THE  MANUFACTURE  OF  LEATHER. 


of  boots  and  shoes,  in  that  they  are  not  dampened  and  tem- 
pered, as  has  been  described  for  heavy  upper  leather.  But  the 
sides,  after  being  scoured,  are  dried  in  heat — in  summer  by 
spreading  them  out  and  exposing  them  to  the  direct  rays  of  the 
sun,  and  in  winter  in  a  room  having  a  temperature  of  at  least 
i  io°  F. 

Pure,  best  ox  tallow,  is  melted  in  the  meanwhile  in  a  port- 
able boiler,  a  temperature  of  1670  F.  being  the  best  for  the 
purpose.  This  temperature  should  be  kept  up  after  the  tallow 
is  melted,  which  can  be  effected  by  keeping  the  boiler  over  a 
small  coal  fire,  or,  still  better,  by  placing  it  in  another  boiler 
with  hot  water,  which  is  kept  hot  over  a  fire  while  the  work  is 
going  on. 

One  of  the  heated  sides  is  then  placed  upon  the  table  and 
the  fluid  tallow  applied  with  a  brush.  The  hide  should  be  so 
thoroughly  saturated  with  the  tallow  as  to  be  entirely  per- 
meated with  it,  and  the  tallow  applied  to  the  flesh  side  so  as  to 
become  visible  upon  the  grain  side.  Should  the  tallow  congeal 
upon  the  surface  before  permeating,  it  is  allowed  to  soak  in  by 
placing  the  hide  in  the  sun  or  near  a  warm  stove ;  but  if  the 
hide  is  already  thoroughly  permeated,  the  excess  of  tallow 
must  be  removed. 

CURRYING  THE  TALLOWED  LEATHER. 

The  sides  having  lost  their  good  appearance  and  become 
dark  by  greasing  with  tallow,  are  soaked  in  water  for  twenty- 
four  hours  and  then  placed  upon  the  beam,  and  the  tallow  still 
adhering  to  the  flesh  side  is  removed  with  a  blunt  knife.  After 
placing  them  again  in  water,  each  side  is  taken  out  separately, 
and  after  spreading  it  upon  the  table  and  covering  with  a  layer 
of  spent  tan  one-half  inch  thick,  it  is  rolled  up,  and  the  roll, 
after  securing  it  with  twine,  beaten  with  a  mallet,  until  the 
leather  has  again  acquired  a  light  color  and  its  original 
suppleness. 

After  rinsing  off  the  tan  the  hides  are  again  beaten,  with 
frequent  dipping  in  water  in  case  they  should  feel  too  dry. 


HARNESS  AND  BELTING  LEATHER. 


They  are  next  smoothed  in  the  same  manner  as  for  the 
ordinary  machine  belt  leather. 

It  is  recommended  to  have  two  men  to  do  the  work,  it 
being  too  fatiguing  for  one. 

The  manufacture  of  this  variety  of  leather,  though  very 
laborious,  repays  doubly  the  work  expended  upon  it,  princi- 
pally by  the  increased  weight  the  leather  acquires  by  the 
absorption  of  tallow. 

CURRYING  STRAP  BUTTS  FOR  MILL  BANDS  AND  ENGINE  BELTS. 

Strap  butts  for  mill  bands  and  engine  belts  are  generally 
made  from  good  domestic  hides,  and  sometimes  from  foreign 
of  good  growth,  which  have  not  been  struck  out  nor  rolled  as 
sole  leather,  but  merely  dried  out  of  the  pits.  The  first  thing 
to  be  done  is  to  thoroughly  soak  them  ;  they  should  then  lay 
down  two  or  three  days  to  mellow,  and  then  be  shaved  lightly 
over,  only  the  rough  flesh  being  taken  off,  the  substance  not 
being  reduced.  Some  do  not  shave  them  at  all,  saying  where 
a  scouring  machine  is  used  that  will  take  off  sufficient;  but 
straps  and  belts  made  from  these  manufacturers'  butts  are  not 
so  good  in  either  wear  or  appearance.  After  shaving  they 
should  be  put  into  water  and  lay  at  least  one  night  and  be  well 
scoured  first  on  flesh,  then  on  grain,  and  be  hung  in  shed  to 
stiffen  previous  to  being  put  in  the  stretching  machine.  Much 
attention  is  required  at  this  stage  that  they  be  dry  enough  to 
retain  the  full  surface  acquired  in  straining,  and  not  too  dry  to 
receive  a  fair  quantity  of  dubbin  in  such  a  state  as  to  amalgamate 
and  form  part  of  the  leather.  We  have  heard  some  professed 
curriers  say  the  stretching  is  unnecessary  and  that  they  dispense 
with  it,  but  their  belts  when  made  are  far  behind  first-class,  and 
must  stretch  themselves  in  use.  Before  the  butts  or  sides  are 
fixed  to  the  machine  we  prefer  having  them  well  set  on  the 
table  on  the  grain  side,  the  flesh  side  having  been  brushed 
over  with  dubbin  sufficient  to  cause  it  to  adhere,  and  yet  ex- 
pand as  it  is  worked  upon.  It  will  then  be  in  a  better  state  for 
yielding  to  the  pressure  required  than  if  done  after  stuffing,  and 


4o8 


THE  MANUFACTURE  OF  LEATHER. 


should  be  lightly  set  after  taking  out  of  stretcher,  and  brushed 
over  with  dubbin  and  laid  in  packs  ready  for  stuffing,  which 
may  be  done  when  all  are  ready  and  hung  to  dry.  These 
should  be  dried  out  before  resetting,  though  they  must  be 
damped  down  after  and  then  well  set,  and  when  re-dried  should 
lay  away  a  time  before  finishing.  A  good  coat  of  tallow  on 
the  grain  before  laying  away  improves  the  quality  and  appear- 
ance. Where  the  butts  are  not  stretched  by  machine,  they 
should  after  scouring  be  well  set  out  on  the  grain  before 
stuffing,  and  when  rather  more  than  half  dry  be  taken  down 
and  thoroughly  set  out  on  the  grain,  and  then  dried  out  and 
reset  before  laying  down  in  stock,  ready  to  be  finished  when 
required. 

TO  REMOVE  GREASE  FROM  LEATHER  BELTING,  ETC. 

The  following  method  of  removing  grease  from  leather  belt- 
ing is  patented  in  Germany  and  consists  in  subjecting  the  belt 
to  a  slow,  dry  heat  after  packing  in  dry  powdered  clay. 

The  belt  to  be  degreased  is  rolled  up  in  a  spiral  in  such  a 
manner  as  to  leave  from  ^  to  y2  inch  space  between  each  con- 
volution. It  is  then  placed  in  a  specially  constructed  box  or 
other  receptacle,  the  bottom  of  which  is  covered  with  a  layer  of 
powdered  clay,  and  the  space  between  the  belt  and  the  sides  of 
the  box,  as  well  as  the  space  between  the  convolutions  of  the 
spiral,  packed  tightly  with  powdered  clay,  the  whole  being 
lastly  covered  with  a  layer  of  the  same. 

The  object  of  packing  in  the  clay  tightly,  as  described,  is 
two-fold,  viz. :  To  prevent  warping  and  to  insure  contact  with 
the  clay  at  every  point,  and  consequent  perfect  cleansing  of  the 
belt.  The  box  with  contents  is  introduced  into  an  oven, 
specially  constructed  so  as  to  give  out  an  even  heat  from  all 
directions,  the  latter  being  an  important  point,  as  irregular 
heating  will  warp  and  spoil  the  belt.  The  baking  process  is 
kept  up  until  all  grease  has  been  extracted,  which  takes  from  8 
to  10  days,  according  to  how  long  the  belt  has  been  in  service, 
and  the  degree  of  heat  to  which  it  is  subjected.   The  hotter  the 


HARNESS  AND  BELTING  LEATHER. 


409 


oven,  the  quicker  the  operation,  but  it  is  not  advisable  to  risk 
using  too  much  heat,  as  the  belt  might  thereby  be  easily  ruined. 

When  satisfied  that  all  the  grease  has  been  extracted,  the 
box  is  removed  and  allowed  to  cool  off  gradually,  or,  better 
still,  is  left  to  cool  off"  with  the  oven.  A  gradual  cooling-off  is 
absolutely  necessary,  as  a  sudden  degree  of  temperature  will 
warp  and  injure  the  belt.  The  precautions  necessary  to  a  suc- 
cessful result,  the  omission  of  all  or  one  of  which  is  fatal,  are: 
Care  in  packing  the  clay  closely  and  tightly;  evenly  distributed 
heat,  and  gradual  cooling  off. 

The  above  process  not  only  removes  every  trace  of  grease,  it 
is  said,  but  also  acts  as  a  preservative  and  stops  all  further 
stretching,  one  of  the  disadvantages  of  new  belts.  Being  a  dry 
process,  it  can  be  applied  without  injury  to  cemented  belts. 

WET  STRETCHING  MACHINE  FOR  BELT  LEATHER. 

Figs.  113  and  114  show  a  vertical  section  and  elevation  of 
a  wet  stretching  machine  for  belt  leather  built  by  the  Vaughn 
Machine  Company,  Peabody,  Mass.  This  machine  is  for  wet 
stretching  belt  leather  and  it  will  do  the  work  thoroughly,  tak- 
ing out  all  the  stretch  and  gaining  largely  in  measurement. 


4io 


THE  MANUFACTURE  OF  LEATHER. 


Fig.  113. 


VERTICAL  SECTION  OF  WET  STRETCHING  MACHINE  FOR  BELT  LEATHER. 


WET  STRETCHING  MACHINE  FOR  BELT  LEATHER. 


CHAPTER  XXVI. 


DANISH  LEATHER. 

Under  the  name  of  "Danish  leather"  is  sold  on  the  market 
not  only  glove  stock  but  also  leathers  for  various  other  pur- 
poses. Owing  to  its  extreme  suppleness,  as  much  as  owing  to 
its  beautiful  color,  this  product  has  long  stood  in  especial  favor 
with  consumers. 

These  desirable  traits  of  Danish  leather  are  secured  mainly 
by  a  most  careful  preparation  of  the  hides  preparatory  to  tan- 
ning, thorough  and  favorable  soaking  and  cleansing,  combined 
with  the  use  of  willow  bark  as  tanning  agent. 

It  is  hardly  necessary  to  say  that  the  best  "  Danish  leather," 
so-called,  comes  from  Denmark  proper.  In  that  country 
spring  water  is  a  rarity,  and  the  many  small  streams  and  lakes 
are  mainly  fed  by  rain-water ;  the  water  is  very  soft,  and  par- 
ticularly well  adapted  for  the  production  from  raw  material 
treated  with  it  of  a  pliable  leather  of  most  excellent  feel.  On 
the  borders  of  these  same  streams  and  lakes  thrive  those  very 
species  of  willow,  whose  valuable  bark  is  almost  exclusively 
used  in  tanning  throughout  Denmark. 

The  leather  obtained  by  this  willow  tannage  is  of  a  light  red, 
pleasing  to  the  eye,  and  is  readily  worked  into  colors,  yellow 
and  brown  shades  being  favorites  among  manufacturers. 

Otherwise  the  tanning  and  currying  differs  but  little  from 
ordinary  processes  for  upper  leather,  the  main  secret  of  success 
lying  in  the  painstaking  manner  in  which  every  detail  of  the 
handling,  from  raw  hide  to  the  finished  article,  is  followed  up. 

Danish  leather,  even  when  intended  for  saddlery  purposes, 
receives  but  little  addition  of  grease,  glycerine  being  used  in- 
stead for  softening  purposes.    This  is  a  method  comparatively 

(4t2) 


DANISH  LEATHER. 


413 


little  known  in  connection  with  the  manufacture  of  other  sorts 
of  leather  except  kid,  and  is  applied  as  follows :  By  means  of 
a  sponge  a  very  thin  coat  of  glycerine  is  rubbed  over  the  flesh 
side  of  the  leather,  which  latter  is  then  folded,  flesh-side  in. 
The  glycerine  by  simply  penetrating  the  leather,  serves  to  re- 
tain its  pliability.  Frequently,  it  is  true,  a  tanner  will  add  a 
small  proportion  of  grease  to  the  glycerine,  or  give  a  light  ap- 
plication of  grease  to  the  leather  after  it  has  become  impreg- 
nated with  the  glycerine. 


CHAPTER  XXVII. 


RUSSET  LEATHER. 

RUSSET  leather  is  usually  made  from  rough  leather  which  is 
very  carefully  selected  for  shoe  leather,  so  as  to  get  it  free  from 
imperfections,  such  as  brier  scratches,  grubs,  salt  stains,  tan- 
ners' hook  marks,  chafed  grain,  arising  from  rough-edged 
workers  in  working  out  of  the  drench  and  from  the  short  hair- 
ing knife. 

Leather  which  is  selected  for  bag  leather  and  printed  with  a 
large  figure  does  not  show  up  the  imperfections  so  plainly; 
and  consequently,  a  lower  grade  of  leather  can  be  used  for  this 
purpose. 

Large  sides  are  used  for  bag  leather  and  for  strap  leather, 
while  the  smaller  sides  are  used  for  shoe  purposes.  The  sides 
employed  for  strap  leather  may  have  some  imperfections,  but 
these  imperfections  may  be  dodged  in  the  cutting.  The  sides 
selected  for  card  leather  and  for  shoe  leather  must  be  pretty 
nearly  perfect. 

The  leather  used  for  United  States  mail  bags  is  russet,  as  is 
also  the  leather  used  for  the  bags  carried  by  the  U.  S.  letter 
carriers,  and  they  may  have  more  imperfections  than  card  or 
shoe  leather.  Leather  which  is  used  for  ladies'  belts  must  be 
free  from  imperfections  if  the  belt  is  not  embossed.  If  it  is  em- 
bossed, it  covers  up  a  lot  of  the  minor  defects. 

The  russet  leather  which  is  used  for  bicycle  seats  and  cases 
must  be  of  high  grade.  The  light  russet  leather  used  for  whip- 
stocks  should  be  of  good  grade.  The  light  russet  leather  used 
for  book-bindings  should  be  high  grade.  There  are  a  large 
number  of  sheep-skins  used  for  this  purpose,  but  bindings  of 
this  character  chip  easily  and  are  not  so  good  as  the  light 

(  414  ) 


RUSSET  LEATHER. 


415 


russet  leather.  The  highest  grade  of  book  bindings  is  made 
from  calf-skins.  Book  bindings  are  also  made  from  large  and 
thick  sides  of  leather  which  are  then  embossed  and  finished  in 
imitation  of  seal  and  natural  grains,  and  then  split  down  very 
thin,  about  one  ounce  to  the  square  foot,  so  as  to  give  the  ap- 
pearance of  a  heavy,  solid  leather  without  the  weight. 

The  straps  which  are  used  in  street  cars  to  hold  to  when  the 
cars  are  crowded,  as  well  as  belt  straps  and  register  straps, 
must  also  be  of  high  grade  russet  leather.  Russet  leather  is 
also  used  for  a  large  variety  of  purposes  which  have  not  been 
mentioned. 

When  the  rough  leather  is  selected  and  delivered  to  the 
currier,  the  first  thing  is  to  round  it  by  cutting  off  the  shanks, 
tails,  teats,  snout  and  other  waste  parts.  The  sides  are  then 
wet  down  and  allowed  to  mull  for  about  twelve  to  twenty- four 
hours.  Then  they  are  put  into  a  pin-wheel  and  milled  for  ten 
minutes,  so  as  to  take  out  the  stiffness  and  get  them  into  better 
condition  for  working.  They  now  contain  about  fifty  per  cent, 
of  water,  and  are  skived  in  this  condition  by  running  them 
through  the  belt  knife  splitting  machine.  The  skiving  is 
simply  for  the  purpose  of  taking  off  the  loose  flesh,  and,  at  the 
same  time,  giving  a  more  even  surface  to  work  upon,  and  it  also 
improves  the  appearance  of  the  split,  which  is  later  on  taken 
from  the  leather,  and  which,  in  most  instances,  is  sold  in  the 
rough  to  the  split  finisher.  The  sides  are  then  worked  on  the 
grain  side  on  the  stoning  jack  made  for  this  special  purpose, 
by  J.  T.  Freeman  &  Co.,  Woburn,  Mass.,  to  take  out  the  stretch 
and  creases  in  the  grain  previous  to  splitting. 

The  sides  are  next  piled  on  a  table  and  sorted  for  thickness. 
They  are  usually  divided  into  light,  medium  and  heavy.  Then 
the  splitting  machine  is  adjusted  so  as  to  take  the  lightest  sides 
first,  the  medium  next  and  the  heavy  last.  The  knife  of  the 
splitting  machine  is  wearing  back  all  the  time,  so  that  when  the 
heaviest  sides  are  fed  to  the  machine  the  edge  of  the  knife  is  in 
the  right  position. 

The  proper  way  to  split  shoe  leather  is  to  preserve  the  nat- 


4i6 


THE  MANUFACTURE  OF  LEATHER. 


ural  lines.  The  side  of  leather  will  finish  best  split  with  a  grad- 
ual taper  from  back  to  belly  and  from  butt  to  shoulder. 

Card  leather  and  strap  leather  have  to  be  split  pretty  nearly 
of  a  uniform  thickness.  The  leather  is  next  given  to  the  shaver, 
who  cuts  it  over  lightly  on  the  flesh  side  to  take  out  any  little 
marks  or  inequalities  left  by  the  belt  knife.  The  leather  is  then 
put  into  the  pin-wheel  with  a  weak  solution  of  borax  or  other 
alkali  and  washed  thoroughly.  While  it  is  still  in  the  wheel,  it 
receives  a  bath  of  weak  sulphuric  acid  or  other  acid  to  neutral- 
ize the  alkali  and,  at  the  same  time,  take  out  any  iron  stains 
that  may  be  in  the  leather. 

The  borax  bath  is  drawn  off  before  the  sulphuric  acid  bath  is 
applied.  The  alkali  bath  works  out  the  dirt  and  makes  the 
leather  appear  much  darker.  The  sulphuric  acid  bath  changes 
the  color  of  the  leather  to  a  much  lighter  shade  than  it  was 
originally. 

The  sulphuric  acid  bath  is  then  drawn  off,  and  the  leather 
receives  a  warm  bath  of  Sicily  sumac  and  alum,  which  makes 
the  leather  of  a  still  lighter  shade  and  at  the  same  time  softens 
it.  The  leather  is  then  rinsed  in  clear  water  in  a  tank  and  is 
immediately  struck  out  on  the  flesh  side  to  remove  the  water 
and  surplus  sumac. 

The  leather  is  now  in  condition  to  dye  or  leave  in  the  natural 
light  color  which  has  been  obtained.  If  the  light  color  is  de- 
sired, the  leather  is  hung  up  and  allowed  to  harden,  as  it  is 
termed  in  the  East,  or  to  sammy,  as  it  is  termed  in  the  West, 
for  setting.  The  setting  is  done  by  swabbing  a  table  over 
lightly  with  oil,  or  paste,  if  no  oil  is  desired  in  the  leather. 
Then  it  is  set  out  on  the  grain  side  with  a  setting  stone,  and 
afterwards  with  a  brass  slicker,  to  take  out  the  stone  marks. 
The  leather  is  then  hung  up.  Some  tanners  hang  it  on  half 
round  sticks ;  others  suspend  it  by  the  head  and  butt  with 
strings  and  allow  it  to  dry.  If  the  leather  is  to  be  printed,  it  is 
next  dampened  with  clear  water  or  flax-seed  gum  or  egg  albu- 
men or  milk,  and  is  printed  with  whatever  figure  is  desired. 
After  it  is  printed,  it  is  grained  with  a  cork  arm  board  and 


RUSSET  LEATHER. 


4'7 


hung  up  to  partly  dry.  Then  the  leather  is  taken  down  and 
soft-boarded  and  hung  up  to  thoroughly  dry.  After  it  is  dry, 
it  is  staked  by  the  staking  machine.  Then  it  is  glazed  with  an 
agate  or  glass  machine,  and  then  it  receives  the  final  graining 
and  is  ready  for  market. 

If  the  leather  is  to  be  dyed,  it  is  put  into  a  vat  after  it  is 
struck  out.  The  vat  is  about  six  feet  square,  and  has  a  circular 
bottom  and  a  paddle  wheel  about  five  feet  long  and  four  feet  in 
diameter,  hung  upon  a  shaft  about  two  inches  in  diameter,  with 
fast  and  loose  pulleys.  This  paddle  will  run  from  eighteen  to 
twenty  revolutions  per  minute.  The  vat  usually  stands  about 
one  foot  above  the  floor,  so  as  to  draw  off  the  exhausted  dye. 
The  vat  is  about  five  feet  deep,  and  is  partitioned  off  at  one 
corner  with  a  well  about  io"x  10",  which  runs  to  the  bottom 
of  the  vat.  The  well  is  pierced  with  auger  holes,  and  the  strong 
dye  is  put  into  the  vat  through  this  well  and  mingled  uniformly 
with  the  water  in  the  tank. 

The  leather  has  already  been  partially  mordanted  by  the 
sumac  and  alum  for  certain  shades.  Some  colors  do  not  re- 
quire any  further  mordant;  but  others  do.  The  colors  used 
are  mostly  anilines.  The  secret,  if  any,  in  dyeing  leather  is  in 
preparing  it  for  dyeing.  Russet  leather  is  dyed  in  a  great  vari- 
ety of  shades.  As  many  as  a  dozen  different  shades,  or  more, 
may  be  obtained  from  the  same  can  of  color.  After  the  dyeing 
is  done,  the  leather  is  struck  out  on  the  flesh  side  and  fat- 
liquored  in  the  pin-wheel,  and  hung  up  to  harden  or  sammy 
previous  to  setting.  The  leather  is  then  finished  in  about  the 
same  way  as  the  light-colored  leather  which  has  been  described. 
27 


CHAPTER  XXVIII. 


GRAIN  AND  SPLIT  LEATHER. 

SATIN  OIL    FINISH  ;    OIL  GRAIN  ;    PLOW    GRAIN  ;    GLOVE  GRAIN  ;  IMITATION 
GOAT  OR  PEBBLE  GRAIN  J   IMITATION   KANGAROO  \  IMITATION  SEAL  ; 
IMITATION  HOG  J  WAX  CRIMPING  SPLITS  J  FLESH  SPLITS  ;  DON- 
GOLA,   BUFFED  LEATHER  AND  FLEXIBLE  SPLITS,  WITH 
STUFFINGS  :   PASTES,   BLACKS,   FINISHES,  ETC. 

In  upper  leather,  buyers  look  for  softness,  suppleness,  pli- 
ability, elasticity  and  waterproof  quality;  in  bending  it  must 
not  break,  must  have  a  nice  grain  and  good  color;  it  must  be 
well  worked,  staked  and  grained  and  possess  durability;  it 
must  have  a  full  and  plump  feeling,  it  must  have  a  delicate 
lustre,  and  the  dear  only  knows  what  more  is  expected. 
Besides  the  above  qualities,  the  buyer  also  looks  for  a  fine 
grain  on  black  leather,  and  this  must  be  uniform,  for  leather  can 
be  considered  handsome  only  when  it  is  uniform.  A  uniform 
grain  insures  it  against  uneven  contraction.  By  considerable 
work  in  slicking  and  setting  out  during  the  currying,  these 
irregular  grains  may  be  worked  out,  but  in  graining  or  board- 
ing it  will  always1  appear  again  to  a  greater  or  less  extent,  and 
never  can  be  entirely  remedied.  This  false,  uneven  grain  may 
be  prevented  in  two  ways,  that  is  by  using  weak  liquors  at  the 
beginning  of  the  tannage  and  by  continued  agitation  while  the 
skins  are  in  the  first  liquors.  In  the  first  instance  there  is  too 
little  tannin  in  the  liquor  to  cause  a  strong  contraction  of  the 
grain,  and  in  the  second  the  constant  bending  of  the  skin  by 
the  agitation  breaks  the  grain  in  every  direction  and  prevents 
any  break  in  one  direction  only.  How  nicely  the  grain  is 
broken  by  agitation  one  can  best  see  illustrated  in  English 
crown  leather,  where  the  grain  in  consequence  of  the  constant 
stretching  and  lifting  of  the  wheel  becomes  so  regular  that  fur- 

(418) 


GRAIN  AND  SPLIT  LEATHER. 


419 


ther  currying  is  not  necessary,  and  the  hide,  so  to  speak,  comes 
finished  from  the  wheel.  The  stronger  the  liquor  is  the  more 
apt  it  is  to  contract  the  hide.  It  is  very  injurious  to  commence 
the  tannage  with  too  strong  liquors,  and  equally  injurious  to 
allow  the  liquors  to  fall  away  in  strength.  Commence  with 
weak  liquors  and  strengthen  them,  keeping  up  a  constant  agita- 
tion, until  the  grain  has  been  formed,  and  the  leather  is  so  far 
tanned  that  the  grain  cannot  contract. 

Satin  oil  finish,  oil  grain,  plow  grain,  glove  grain,  imitation 
goat  or  pebble  grain,  imitation  kangaroo,  imitation  seal,  imita- 
tion hog,  wax  crimping  splits,  flesh  splits,  dongola  and  buffed 
leathers  are  produced  in  large  quantities  in  the  United  States  in 
Massachusetts,  New  York,  Pennsylvania,  Illinois,  Michigan  and 
Wisconsin. 

The  bark  used  for  the  tannage  of  these  leathers  is  hemlock, 
and  is  derived  principally  from  Pennsylvania,  Michigan,  Wis- 
consin and  Canada. 

The  hides  used  are  chiefly  slaughter  hides,  and  are  obtained 
from  Chicago,  Illinois,  St.  Louis  and  Kansas  City,  Missouri, 
Cleveland,  Dayton  and  Cincinnati,  Ohio.  Boston,  Massachu- 
setts, and  other  points  in  New  England  furnish  a  few  hides,  but 
the  supply  from  the  latter  sources  is  small. 

The  hides  used  for  the  varieties  of  leather  under  considera- 
tion are  "buff  hides,"  i.  e.,  those  obtained  from  cows,  heifers, 
and  steers,  and  will  average  to  weigh  about  fifty  pounds  each. 

The  first  step  in  preparing  them  for  the  tanning  liquor  is  to 
place  the  hides  in  the  soaks  of  clean,  cold  water,  and  here  they 
usually  remain  two  or  three  days,  the  water  being  changed 
every  day. 

In  soaking  the  hides  they  are  placed  on  a  stick  the  length  of 
the  back-bone,  then  they  are  hung  low  enough  in  the  pit  to  be 
covered  by  water,  which  does  away  with  the  hoisting  of  the 
hides  out  of  water.  The  plug  is  drawn  each  twenty-four  hours 
and  the  water  run  off.  The  vats  are  rinsed  of  salt  and  sedi- 
ment and  fresh  water  run  in. 

The  pits  must  be  fixed  for  this  process  by  a  stick  on  each 


420 


THE  MANUFACTURE  OF  LEATHER. 


side  with  pins  far  enough  apart  to  admit  the  sticks  upon  which 
the  hides  are  hung,  and  low  enough  to  be  covered  by  water. 

After  being  removed  from  the  soaks  the  hides  are  split  into 
sides,  and  after  being  split  the  sides  are  fleshed  by  machinery, 
and  are  then  rinsed  in  clear  water  and  are  toggled  or  tied  to- 
gether and  then  placed  in  the  limes,  where  they  remain  for 
from  five  to  seven  days,  being  reeled  into  a  vat  of  stronger 
lime  each  day.  The  power  reel  is  used  in  some  factories  and 
the  hand  reel  in  others. 

The  limes  must  be  cleaned  every  14  days,  beginning  at  head 
lime  and  cleaning  every  other  day.  This  gives  clean  limes 
every  14  days,  and  the  hides  come  out  uniform  from  the  limes 
and  are  ready  for  the  bate  and  the  wash  reel. 

The  object  of  liming  is  to  get  the  hair  off,  not  to  eat  the 
gluten  of  the  hide  up.  The  sooner  you  lime  and  get  the  hair 
off,  the  less  bating  required.  If  you  eat  the  gluten  out  you 
have  nothing  to  build  on  for  weight.  This  gives  more  weight 
and  a  closer  and  finer  split,  better  flanks  and  heads. 

The  sides  are  next  unhaired,  which  is  accomplished  usually 
by  the  machine  process.  Eight  hundred  sides  of  leather  can 
be  unhaired  in  one  day  of  ten  hours  by  the  machine  method. 

When  unhaired  by  machinery  the  sides  are  passed  through 
a  Vaughn  or  Whitney  unhairing  machine,  and  are  then  re- 
fleshed  by  machinery  to  take  off  the  flesh  "puffed  up"  or 
raised  by  liming  or  left  on  after  the  first  fleshing. 

The  unhairing,  fleshing  and  refleshing  machines  are  fully  ex- 
plained and  illustrated  in  Chapter  VIII. 

When  the  sides  are  unhaired  and  fleshed  in  this  manner  by 
machinery  they  are  placed  in  a  bate  of  hen  manure  (but  pigeon 
manure  is  better),  in  which  they  remain  from  twelve  to  thirty- 
six  hours,  but  when  the  sides  are  worked  in  the  bate  with  the 
England  wheel  shown  in  Figure  35,  the  bating  can  be  accom- 
plished in  six  to  eight  hours,  the  time  depending  upon  the 
weight  of  the  hide  and  other  circumstances,  the  object  of  the 
bate  being  to  fully  neutralize  the  lime,  thereby  giving  a 
smoother  grain  to  the  leather. 


GRAIN  AND  SPLIT  LEATHER. 


42  I 


After  being  removed  from  the  bate,  the  sides  are  allowed  to 
remain  over  night  in  a  vat  of  clean,  cold  water,  and  are  then 
worked  out  and  short  haired  and  washed  in  a  wheel  with  a 
stream  of  water  heated  to  700  F.  for  two  to  three  minutes. 
When  the  water  runs  off  clear  from  the  wheel  it  should  be 
stopped,  as  the  object  of  the  washing  is  then  accomplished. 
The  sides  are  then  tacked  to  sticks  and  suspended  in  the 
"  handlers,"  containing  hemlock  liquor,  which  is  increased  from 
about  three  degrees  strength  at  the  start  to  twelve  degrees 
strength  at  the  finish.  The  sides  are  treated  in  these  handler 
vats  for  about  twenty-two  to  thirty  days,  being  shifted  contin- 
uously or  daily  into  stronger  liquor.  Some  manufacturers  al- 
low a  small  stream  of  liquor  to  run  continuously  into  the  vats; 
others  strengthen  the  liquor  daily. 

After  being  removed  from  the  sticks,  they  are  allowed  to 
drain  for  a  few  hours  and  are  then  pressed  in  a  power  press 
sufficiently  dry  for  the  splitting  machine.  They  are  next 
skived,  usually  by  a  belt-knife  machine  shown  in  Chapter  XIII., 
one  man  being  enabled  by  a  machine  of  this  character  to  skive 
1000  sides  in  one  day  of  ten  hours.  They  are  then  stoned  out 
on  a  Vaughn  machine  (Chapter  XVI.),  similar  in  construction 
to  the  setting-out  machine;  which  machine  will  stone  out 
1000  sides  a  day,  or  on  a  stoning  jack,  shown  in  Fig.  39.  They 
are  then  fitted  or  trimmed  on  a  table  with  an  ordinary  shoe 
knife  and  are  next  split,  usually  by  the  same  kind  of  a  belt- 
knife  machine  which  has  been  mentioned.  Two  men  will  split 
from  500  to  1000  sides  in  one  day  of  ten  hours  ;  about  2  ^  to  6 
ounces  grain  to  the  square  foot  being  usually  taken  off  the 
side  in  splitting  it,  depending  upon  the  kind  of  leather  which 
it  is  desired  to  produce. 

The  "split"  is  then  trimmed  by  hand,  and  is  then  run  in  a 
pin-wheel  with  weak  liquor  for  15  or  20  minutes  to  take  off  the 
glaze  caused  by  splitting,  and  then  placed  back  in  liquor  of 
about  eight  degrees  strength,  which  is  gradually  increased  and 
remains  for  from  twelve  to  fifteen  days  and  sometimes  longer. 

The  part  from  which  the  "  split  "  is  taken,  called  the  "grain," 


422 


THE  MANUFACTURE  OF  LEATHER. 


is  shaved  on  a  beam  with  a  currier's  knife  in  order  to  take  off 
any  flesh  or  lumps  which  may  be  left  on  the  thin  flanks.  One 
man  will  shave  from  fifty  to  five  hundred  sides  in  a  day,  de- 
pending upon  the  amount  of  work  which  the  shaver  has  to  do  ; 
sixty  sides  being  a  regular  day's  work,  provided  they  are 
shaved  all  over. 

They  are  then  milled  with  either  sumac  or  hemlock  liquor, 
or  both,  for  about  one-half  hour  in  a  revolving  drum,  which  is 
commonly  about  eight  feet  in  diameter  and  four  feet  wide. 

After  being  removed  from  the  liquor  they  are  next  scoured 
in  some  few  establishments,  but  scouring,  unfortunately  for  the 
quality  of  the  leather,  has  become  a  thing  of  the  past  in  many 
of  the  large  factories.  After  being  scoured,  if  this  is  done,  the 
sides  are  hung  over  poles  and  exposed  to  the  air  to  harden,  as 
shown  in  Fig.  115.  They  are  then  taken  down  from  the  poles 
and  the  dry  spots  dampened  and  are  piled,  and  left  to  equal- 
ize for  twenty-four  hours.  They  are  then  carried  to  the  shop 
and  stuffed  in  a  revolving  drum,  such  as  has  been  explained 
and  illustrated  in  Chapter  XV. ;  the  operation  of  stuffing  lasting 
from  about  thirty  to  sixty  minutes ;  the  drum  being  at  a  tem- 
perature of  1600  F.,  and  the  grease  at  a  temperature  of  1400  F. 

Tannages  are  not  all  alike  and  of  course  cannot  all  be 
handled  alike.  The  leather  ought  to  be  from  three  to  four 
days  ahead  of  the  mill  so  as  to  be  well  mulled.  Sometimes  the 
leather  is  a  little  damper,  then  the  mill  and  grease  both  ought 
to  be  a  little  hotter  and  run  somewhat  longer.  In  hot  weather 
the  leather  must  be  turned  every  day  to  prevent  heating. 

After  being  stuffed,  as  soon  as  they  are  cool,  they  are  thor- 
oughly set-out,  hung  up  and  dried.  They  are  then  buffed  and 
whitened,  the  grains  are  buffed  and  the  splits  are  whitened. 

These  leathers  are  all  stuffed  differently.  Satin  grain,  four 
ounces  to  the  square  foot,  is  stuffed  from  40  to  45  per  cent,  of 
its  wet  weight;  the  stuffing  being  35  per  cent.  English  degras, 
35  per  cent,  brown  grease,  15  per  cent,  stearine,  15  per  cent, 
wax. 

Glove  grain,  four  ounces  to  the  square  foot,  being  stuffed 


GRAIN  AND  SPLIT  LEATHER. 


42  3 


424 


THE  MANUFACTURE  OF  LEATHER. 


about  25  to  35  per  cent,  of  its  wet  weight  according  to  its  tan- 
nage. The  stuffing  is  composed  of  35  per  cent.  English  degras, 
65  per  cent,  brown  grease. 

Imitation  goat  or  pebble  grain,  4  ounces  to  the  square  foot, 
is  stuffed  lighter  still,  from  15  to  20  per  cent,  of  its  wet  weight. 
The  stuffing  is  composed  of  30  per  cent,  degras,  and  35  per 
cent,  paraffin  oil,  and  35  per  cent,  cod  oil. 

Kangaroo  and  dongola  are  stuffed  20  per  cent,  with  French 
degras.  This  is  all  the  stuffing  they  get  until  they  go  on  the 
setting-out  table,  when  they  receive  a  coat  of  cod  oil  on  grain 
side.  The  next  day,  after  being  stuffed,  the  sides  are  set  out, 
this  now  being  done  by  the  large  firms  with  machinery. 

The  Vaughn  setting-out  machine  for  splits  and  stuffed  leath- 
ers is  shown  in  Chapter  XVI.  It  is  built  by  the  Vaughn  Ma- 
chine Co.,  Peabody,  Mass. 

The  sides  are  then  struck  out  on  the  flesh  by  hand  with  a 
thin,  sharp  slicker,  and  then  hung  up  to  dry.  They  are  taken 
down  when  dry  and  carried  to  the  finishing  room  and  stained 
on  the  grain  side  with  a  preparation  of  logwood  and  soda;  one 
pound  of  logwood  chips  to  one  gallon  of  water,  two  ounces  of 
sal  soda  being  used  to  the  gallon  of  staining.  The  sides  are 
then  immediately  blacked  with  a  solution  of  copperas  or  other 
preparation  of  iron.  Generally  eight  pounds  of  copperas  to 
the  barrel  of  water  is  used,  the  barrel  holding  usually  fifty 
gallons. 

The  staining  and  blacking  is  usually  done  with  the  Batchelder 
Blacking  Machine,  shown  in  Figs.  73  to  82. 

This  blacking  is  for  satin  oil,  glove  grain,  plow  grain,  oil 
grain  and  dongola.  Imitation  goat  requires  a  weaker  solution, 
about  five  pounds  copperas  to  the  barrel  of  water  being  suf- 
ficient. 

Satin  oil,  after  being  blacked,  is  hung  up  until  the  blacking 
dries  in  ;  take  down,  soft  board,  trim  and  roll,  then  give  two 
coats  of  Victor  No.  50  and  Oil  Finish  Mixed  y2  and  y2.  When 
most  dry,  roll  and  give  another  coat  of  same  finish,  then  roll. 
Always  roll  while  finish  is  a  little  moist.    Leather  treated  as 


GRAIN  AND  SPLIT  LEATHER. 


above  will  come  out  with  a  strong  black  color  and  a  dull  face 
finish,  well  filled  and  a  nice  smooth  feel. 

Bright  glove  grain,  after  being  blacked,  is  taken  down  and 
rolled  with  a  smooth  roller  in  a  Combs  or  Freeman  jack, 
and  then  hung  up  over  night  and  taken  down  next  morning, 
trimmed  and  pasted ;  reduce  paste  with  Victor  Finish  No. 
30,  this  softens  paste  and  gives  a  strong  color.  When  dry 
stake  and  roll,  then  give  two  or  three  coats  of  Victor  Glove 
Finish,  and  when  dry  roll ;  always  let  each  coat  dry  before 
applying  another,  have  one  man  put  on  and  another  follow 
with  fine  sponge  to  streak  off.  This  gives  you  a  very  bright 
and  black  water-proof  finish.  Leather  will  be  well  filled  and 
have  a  nice  soft  feel,  and  it  is  then  ready  for  market. 

Imitation  of  goat  or  pebble  grain  is  finished  as  follows : 
after  blacking  take  and  size  the  sides  with  one  coat  of  sizing, 
hang  up  for  five  minutes  until  dry,  and  pebble  it  by  machine, 
grain  it  four  ways,  straight  and  across,  then  angle  it  two  ways, 
give  the  side  a  coat  of  Victor  No.  4  finish,  hang  up  all  night, 
and  the  next  morning  stake  or  soft  board  and  grain  two  ways, 
give  another  coat  of  Victor  No.  4  finish,  run  it  through  polish- 
ing wheel,  grain  it  two  ways,  oil  it  with  hot  paraffin  oil,  and  it 
is  finished  ready  for  market. 

Kangaroo  chrome  tannage,  is  finished  as  follows:  after 
scouring,  black  it  while  wet,  when  blacked  strike  out  on  flesh, 
turn  it  over  and  slick  on  grain  side,  give  a  heavy  coat  of  fish 
oil,  hang  up  till  dry,  then  trim  it  and  stake  it,  soft  board  it, 
roll  or  glass,  then  the  sides  are  ironed  with  hot  irons,  such  as 
are  used  in  any  laundry,  and  it  is  finished  with  two  coats  of 
Victor  dull  finish,  and  it  is  ready  for  market. 

Crimping  splits  are  provided  from  the  portion  of  the  hide 
after  the  grain  is  split  oft",  and  are  finished  on  the  grain  side. 
They  weigh  from  4  lbs.  to  8  lbs. 

The  splits  are  put  back  in  the  liquors  of  10°  strength  for  10 
days  to  15  days,  and  from  the  liquors  they  are  hung  up  till  dry, 
then  taken  down  and  dampened  and  left  to  equalize  for  24 
hours,  stuffed  with  grease,  composed  of  25  per  cent,  degras,  50 


426 


THE  MANUFACTURE  OF  LEATHER. 


per  cent,  hard  or  brown  grease,  and  25  per  cent,  of  wax;  they 
are  stuffed  35  per  cent,  of  their  wet  weight.  The  stuffing  is 
done  in  a  drum,  heated  to  1650  F.,  and  stuffing  is  heated  to 
1400  F.  The  splits  are  then  set  out  and  hung  up  till  dry. 
They  are  then  taken  down  and  piled  full  length  for  about  one 
week  on  the  floor,  then  they  are  cut  over  on  flesh  side  and  are 
then  whitened  by  machinery  on  the  grain  side.  One  machine 
does  both  the  cutting  over  and  whitening,  and  will  do  about 
300  splits  per  day  of  10  hours. 

Then  the  splits  are  pasted  on  flesh  side  with  Batchelder 
blacking  machine,  and  then  glassed  over  the  paste  with  a  glass- 
ing machine  ;  then  they  are  blacked  with  lamp-black  blacking 
on  the  grain  side  and  glassed  while  wet;  they  are  then  pasted 
over  the  blacking  and  glassed  again  with  a  glassing-jack ;  they 
are  then  hung  up  all  night,  and  taken  down  next  morning  and 
trimmed,  glassed  on  both  sides  with  glassing-jack;  then  they 
are  finished  with  a  solution  of  gum  tragacanth,  mixed  with  % 
paste  and  ^3  gum  tragacanth  solution.  This  solution  is  made 
by  placing  8  pounds  of  gum  tragacanth  in  8  gallons  of  water, 
and  then  adding  water  each  day  until  it  has  come  to  the  de- 
sired consistency.  The  solution  is  thoroughly  stirred  two  or 
three  times  each  day;  then  add  4  quarts  of  Irish  moss  solution. 
The  solution  of  Irish  moss  is  made  by  taking  10  pounds  of 
Irish  moss  to  one  barrel  of  water  and  boiling  for  l/2  hour. 
Then  add  one  quart  of  cod  oil,  which  completes  the  finish  for 
wax  crimping  splits. 

GUM  TRAGACANTH  FINISH. 

To  make  10  gallons  of  finish,  take  four  pounds  gum  traga- 
canth and  one  quart  of  cod  oil,  and  dissolve  them  together 
over  night.  Next  morning  pour  three  gallons  of  water  at  the 
boiling  point  on  the  mixture.  Leave  alone  for  four  hours. 
Then  stir  well,  and  next  day  add  four  more  gallons  of  boiling 
water.  Stir  occasionally  and  add  two  more  gallons  of  boiling 
water  a  few  days  afterwards.  If  too  heavy,  add  more  hot 
water,  and  the  mixture  will  then  be  ready  for  use.    The  cod 


GRAIN  AND  SPLIT  LEATHER. 


oil  will  take  the  dry  tendency  from  the  gum,  and  when  applied 
to  the  leather  will  give  a  fine  moist  feel.  If  made  as  directed, 
this  mixture  will  remain  good  and  ready  for  use  for  five  years. 
It  is  specially  valuable  for  shoe  shops.  It  will  be  found  that 
the  method  here  given  for  dissolving  the  gum  is  much  better 
than  when  only  water  is  employed.  If  water  is  hard,  add  a 
little  borax. 

PASTE  FOR  UPPER  SPLITS  AND  CALFSKINS. 

Mix  seven  pounds  flour;  seven  ounces  dry  rosin  ;  one  gill 
ammonia ;  twenty  ounces  soap  ;  two  pounds  white  glue ;  six 
pounds  tallow. 

This  paste,  when  applied  in  connection  with  the  above  prep- 
aration of  tragacanth,  should  be  used  in  the  proportion  of 
three-quarters  of  it  to  one-quarter  of  the  prepared  tragacanth. 
It  will  make  a  fine  finish  that  will  not  peel  or  crack  off.  If  the 
leather  is  open,  use  a  trifle  more  paste  to  fill  up. 

BLACKING  FOR  SPLITS. 

1 8  pounds  of  Babbit  soap;  10  pound  barrel  lamp-black;  50 
gallons  of  water. 

Pyrolignous  acid  black  is  the  best  black  to  use  for  fine  work. 

PASTE  FOR  WAX  STOCK. 

Will  make  about  a  ten  gallon  keg:  Five  quarts  flour,  10 
ounces  tallow  cake,  4  ounces  rosin,  6  ounces  beeswax,  18 
ounces  soap. 

This  makes  a  nice  filler  and  gives  fine  feel  to  leather.  Will 
not  peel  off.  Don't  put  the  soap  in  until  the  other  materials 
have  been  cooking  one-half  hour.  Then  add  the  soap,  having 
previously  cut  it  up  fine,  and  stir  till  it  is  thoroughly  dissolved. 
The  ingredients  will  readily  dissolve  and  the  paste  be  ready  for 
use,  one  hour  after  being  made.    Stir  well  when  cooking. 

IMITATION  SEAL  AND  HOG. 

Imitation  seal  and  imitation  hog  are  printed  with  rollers, 
which  imitate  the  grains  of  those  skins  and  are  finished  as  is 


428 


THE  MANUFACTURE  OF  LEATHER. 


bright  grain.  An  embossing  machine  should  be  used  in  prefer- 
ence to  a  pebble  for  producing  these  grains. 

PLOW  GRAIN. 

Plow  grain  is  made  from  40  to  50  pound  hides,  split  in 
two  in  the  hair.  They  are  soaked  and  limed  in  the  usual 
way.  They  are  unhaired  and  fleshed  by  machinery,  after 
which  they  are  bated  in  a  bate  of  chicken  manure,  1  y2  barrels 
to  60  hides,  in  an  England  wheel.  The  bate  is  steam  heated 
to  900  F.,  and  is  run  for  three  hours,  or  until,  in  the  judgment 
of  the  tanner,  the  sides  are  run  down  low  enough.  After  being 
bated  they  are  washed  in  a  drum  with  clean  warm  water;  the 
water  is  heated  by  a  jet  of  steam  to  about  ioo°  F.  Then  they 
are  taken  to  the  tanyard  and  hung  on  sticks  in  a  weak  liquor 
of  about  50  Barkometer.  Next  day  this  liquor  is  pumped  off 
and  thrown  away.  The  liquor  is  then  renewed  each  day  for 
IO  days,  being  gradually  increased  in  strength  up  to  10  or  12° 
Barkometer.  At  the  end  of  this  time  they  are  taken  off  the 
sticks  and  laid  away  in  liquor  of  180  Barkometer  for  7  days,, 
at  the  end  of  which  time  they  are  taken  up  and  given  a  second 
layer  of  20°  Barkometer,  where  they  remain  for  8  days  longer. 
They  are  then  taken  up  again  and  should  lay  on  top  of  the 
vats  for  2  or  3  days,  when  they  are  ready  to  sammy  (or  semi- 
dry)  for  splitting  machine.  In  cramped  quarters,  when  it  is 
not  possible  to  sammy  the  sides  properly,  a  power  press  can 
be  used.  The  leather  is  next  jacked  on  a  stoning  jack  to  take 
out  the  wrinkles,  and  is  next  skived  on  a  belt-knife  machine, 
and  is  next  split  to  7  or  7^  ounces  to  the  foot  thickness,  and 
then  shaved.  The  leather  is  then  again  sammied  and  dampened 
for  stuffing,  which  is  done  in  a  wheel  heated  to  1 60°  F.,  and 
the  grease  is  heated  to  1400  F.  The  stuffing  is  45  to  50  per 
cent,  of  the  dry  weight  of  the  leather,  and  is  composed  of  60 
per  cent,  hard  brown  grease,  20  per  cent,  stearine,  and  20  per 
cent.  English  degras. 

The  leather  is  then  set  out  either  by  machine  or  hand,  and 
hung  to  dry,  and  when  dry,  which  usually  requires  three  days. 


GRAIN  AND  SPLIT  LEATHER. 


429 


is  taken  down  and  snuffed  with  a  buffing  slicker.  The  leather 
is  then  stained  and  blacked  in  the  usual  way,  and  is  then 
pebbled  with  a  boot  grain  print,  and  boarded  on  the  grain 
three  ways,  angled  two  ways  and  across  from  back  to  belly. 
The  leather  is  then  given  a  coat  of  heavy  oil,  composed  of  one 
gallon  paraffin  oil  and  two  pounds  degras,  and  hung  up  to  dry 
over  night.  In  the  morning  it  is  boarded  again  three  ways  on 
the  grain  the  same  as  before,  and  is  then  soft  boarded  and 
given  a  light  coat  of  oil.  The  oil  is  composed  of  one  gallon 
of  paraffin  oil  and  one  pound  of  degras.  It  is  then  hung  up 
until  the  oil  strikes  in,  and  then  taken  down  and  given  a  coat 
of  finish,  the  usual  satin  finish. 

FLESH  SPLITS. 

Flesh  splits  are  splits  which  are  finished  on  the  flesh  side. 
The  usual  weight  of  the  flesh  splits  is  from  lyi  to  3^  pounds. 
The  splits  are  taken  from  the  splitting  machine,  and  shaved  on 
the  flesh  side,  and  any  large,  loose  veins  should  be  entirely 
shaved  out.  The  small,  close  veins  should  be  merely  split  in 
the  shaving.  After  shaving,  the  splits  should  be  run  through 
the  splitting  machine  and  leveled  from  the  grain  side.  They 
should  then  be  sammied  and  dampened  ready  for  stuffing, 
which  is  55  per  cent,  of  their  dry  weight. 

The  stuffing  should  be  composed  of  the  following  greases: 
70  pounds  Brown  grease ;  20  pounds  English  degras ;  20 
pounds  refined  paraffin  wax. 

This  is  for  170  lbs.  of  dry  splits.  The  drum  is  heated  to 
1600  F.  and  the  stuffing  to  1400  F.  The  splits  should  be  run 
in  the  stuffing  wheel  for  thirty  minutes,  after  which  they  should 
be  taken  out  and  hung  up  to  cool  for  about  thirty  minutes,  then 
taken  down  and  placed  in  a  pile  opened  out  flat,  and  allowed  to 
remain  in  the  pile  until  the  next  day.  They  should  then  be  set 
out  on  both  sides  by  machine  or  hand,  and  hung  up  to  dry  which 
would  require  about  three  days.  The  splits  should  then  be  taken 
down  and  piled  lengthwise  on  the  floor  and  allowed  to  remain 
for  about  a  week  in  piles.    They  are  then  ready  for  whitening, 


43© 


THE  MANUFACTURE  OF  LEATHER. 


which  is  done  by  hand  with  a  whitening  slicker.  The  veins 
should  be  cut  out  the  same  as  a  calf  skin,  and  they  should  then 
be  cut  over  lightly  on  the  back  and  given  a  coat  of  paste  on 
the  back;  the  paste  should  be  mixed  with  quercitron  extract, 
and  hung  up  to  dry.  They  are  then  glassed  by  machine  on  the 
pasted  side  and  then  blacked  on  the  flesh  side  and  glassed  out 
by  machine,  after  which  they  are  pasted  on  the  black  and  hung 
up  and  dried  out. 

The  splits  are  then  glassed  out  of  paste  by  machine  and 
given  a  coat  of  oil  if  necessary,  and  are  then  given  a  coat  of 
gum  for  a  finish. 

The  finish  coat  should  consist  of  ^  paste  and  i/j  of  dissolved 
gum  tragacanth. 

Oil  grain  is  finished  the  same  as  plow  grain,  only  it  is  a 
lighter  leather,  5  or  6  ounces  to  the  foot,  and  has  a  smaller 
pebble. 

The  bright  finish  for  glove  grain  is  composed  as  follows  for  100 
gallons:  10  lbs.  borax  to  12  gallons  of  water.  The  borax  is 
boiled  thoroughly  in  a  kettle  or  tank  with  steam  for  y2  hour,  or 
until  borax  is  thoroughly  dissolved.  Then  50  lbs.  of  "  Gernet 
Diamond  C  "  shellac  is  thrown  into  the  borax  water,  stirred  thor- 
oughly, and  boiled  till  the  shellac  is  all  dissolved,  which  re- 
quires about  1  hour.  Then  take  75  lbs.  of  logwood  chips  and 
place  them  in  a  second  kettle  and  pour  over  them  75  gallons  of 
water  and  boil  r  hour  with  steam. 

If  a  blue-black  color  is  desired,  dissolve  y2  ounce  of  bi- 
chromate of  potash  to  every  2  lbs.  of  logwood  used  and  add  it 
to  the  logwood  liquor. 

The  logwood  liquor  is  then  poured  into  the  shellac  solution ; 
both  the  shellac  solution  and  the  logwood  solution  must  be  at 
boiling  point.  The  two  solutions  should  be  thoroughly  stirred 
for  15  or  20  minutes,  and  then  left  for  24  hours  until  cold. 
Then  take  25  lbs.  of  blood  albumen  and  pour  over  it  5  gallons 
of  water  and  allow  it  to  soak  for  10  hours,  then  stir  well  and 
pour  it  into  the  logwood  and  shellac  solution,  stir  well  and  then 
add  21  gallons  of  beef  blood  under  constant  stirring.    Then  add 


GRAIN  AND  SPLIT  LEATHER. 


431 


2  gallons  of  ammonia,  stirring  well,  then  put  in  2  ounces  of 
carbolic  acid  to  prevent  the  blood  from  smelling.  The  quan- 
tity of  ammonia  is  not  fixed,  as  some  leather  will  take  more 
ammonia  than  others — in  such  cases  the  ammonia  is  added  at 
the  finishing  shops.  This  finish  is  put  on  the  leather  by  two 
men,  one  putting  it  on  and  the  other  striking  it  off  after  him. 
They  both  use  fine,  soft  sponges.  They  give  the  leather  two 
to  three  coats  in  addition  to  the  paste,  and  it  is  hung  up  to  dry 
for  y2  hour  after  each  coat. 

Satin  oil  leather  is  finished  as  follows:  It  is  made  by  putting 
on  the  leather  one  coat  of  bright  glove  finish,  then  take  four 
quarts  of  the  gum  tragacanth  solution,  one  pint  of  flour  paste, 
one  and  one-half  pints  of  cod  oil,  one  and  one-half  pints  of  de- 
gras,  then  strain  well  with  sieve  or  cheese  cloth  and  put  on  the 
leather  one  coat  of  this  mixture  over  the  bright  glove  finish. 
This  finish  is  put  on  in  the  same  way  as  the  bright  glove  finish. 

Imitation  of  goat  or  pebble  grain  finish  is  made  as  follows : 
Four  quarts  of  Irish  moss  solution,  four  quarts  of  flaxseed 
solution,  four  quarts  of  solution  of  sumac,  six  quarts  of  beef 
blood,  add  one  gill  of  ammonia.  Two  coats  of  this  solution 
are  put  on. 

Kangaroo  finish  is  made  as  follows :  Sixteen  gallons  of  log- 
wood solution  (prepared  as  in  bright  glove  finish),  fourteen 
gallons  of  beef  blood  and  ten  pounds  of  blood  albumen  (soaked 
as  in  bright  glove  finish),  fifteen  gallons  of  gum  tragacanth 
solution  (as  in  bright  glove  finish),  then  add  one  ounce  of  car- 
bolic acid.  Two  coats  are  put  on.  This  is  for  chrome  or  bark 
tanned  stock. 

Very  bright  pebble  grain  finish,  soft  and  greasy  feel :  Blood 
albumen,  one  pound;  water,  one-half  gallon.  Soak  over  night 
cold,  then  add  one-half  gallon  luke-warm  water,  stirring  thor- 
oughly. Strain  through  a  cheese  cloth.  Then  take  one  gallon 
of  blue-black  liquor  and  stir  into  it,  and  then  take  one-half  gill 
glycerine,  one-half  gill  of  ammonia,  mix  thoroughly  and  stir 
into  the  above. 


432 


THE  MANUFACTURE  OF  LEATHER. 


If  you  wish  to  obtain  the  most  satisfactory  results  never 
attempt  to  make  your  own  finish,  as  there  are  manufacturers 
who  make  a  specialty  of  finish  who  can  always  serve  you  at  a 
low  price,  and  often  give  you  valuable  information  in  regard  to 
stuffing  and  finishing  the  various  kinds  of  leather. 

BLUE-BLACK  LIQUOR  FOR  FINISHES. 

Two  pounds  best  logwood  chips,  one-half  ounce  bichromate 
potash,  one  gallon  water. 

BUFFED  LEATHER. 

After  the  leather  has  been  scoured,  either  by  hand  or 
machinery,  it  is  pressed  dry  enough  to  set,  after  which  it  is  "  set 
out"  on  the  grain  side  with  a  stone  so  as  to  make  it  solid,  and 
free  it  from  the  grain,  and  it  is  then  stuffed.  This  variety  of 
leather  is  usually  stuffed  in  the  wheel,  but  is  often  stuffed  by 
hand,  and  it  is  performed  by  laying  the  side  of  leather  on  a 
table,  flesh  side  up,  and  working  over  it  with  a  steel  slicker, 
after  which  a  preparation  of  fish  oil  and  tallow  is  applied  with  a 
brush  to  the  flesh  side.  The  sides  are  then  hung  up  in  the  loft 
to  dry,  being  placed  on  sticks  in  tiers,  and  in  this  manner  they 
remain  until  dry. 

The  superfluous  grease  is  then  removed  from  the  flesh  side  by 
means  of  a  slicker;  but  sometimes  this  operation  is  performed 
by  a  machine,  which  is  called  by  the  curriers  a  "  grease  jack." 

The  leather  is  now  in  condition  for  buffing,  which  is  per- 
formed by  placing  the  side  on  a  slanting  table  covered  with 
leather,  and  removing  the  grain  by  means  of  a  whitening  or 
buffing  slicker.  One  man  will  buff  from  fifty  to  seventy  sides 
of  leather  per  day,  the  number  varying  with  the  condition  of 
the  leather  and  the  skill  of  the  workman,  or  the  buffing  can  be 
done  by  machinery.  In  order  to  improve  the  appearance  of 
the  edges,  the  sides  after  being  buffed  are  next  trimmed  around 
with  a  common  shoe  knife. 

They  are  then  placed  on  a  flat  table,  fifty  sides  being  piled 
one  on  top  of  another  with  the  grain  up,  and  the  batch  is  then 


GRAIN  AND  SPLIT  LEATHER. 


433 


blackened  with  a  composition  of  logwood,  water  and  sal  soda, 
which  is  rubbed  into  the  leather  with  an  ordinary  blacking 
brush,  or  the  sides  may  be  blackened  by  machinery. 

After  the  pack  has  been  thus  treated  the  sides  are  then 
blackened  with  another  compound  of  copperas  water  or  other 
iron  preparation. 

The  sides  are  then  replaced  upon  the  table,  and  are  then 
"  smutted,"  which  operation  is  performed  usually  by  working 
over  the  blacking  with  a  woolen  cloth  in  order  to  remove  dirt 
and  sediment,  and  improve  the  appearance  of  the  blacking. 

The  leather  is  next  glassed  in  order  to  make  it  "  fine,"  and 
remove  all  the  creases,  and  when  the  glassing  is  done  by  hand 
the  side  is  placed  on  a  table  and  the  blacked  portion  worked 
over  with  a  glass  slicker.  The  sides  are  then  hung  up  in  the 
finishing  room  for  a  short  time,  and  then  "  pasted,"  which  is 
an  application  of  flour  paste  over  the  blacking,  and  commonly 
put  on  by  means  of  a  sponge.  After  being  thoroughly  dried, 
the  sides  are  "  soft-boarded  "  by  working  them  with  the  flesh 
side  up,  and  one  man  will  soften  about  100  sides  per  day. 

The  leather  is  then  laid  upon  the  table  and  slicked  off  clean 
on  the  flesh  side,  and  then  immediately  glassed  on  the  grain 
side,  after  which  it  is  gummed  with  a  preparation  of  gum  tra- 
gacanth,  made  of  about  the  consistency  of  jelly,  and  applied 
over  the  paste. 

The  sides,  after  being  hung  up  and  dried,  are  then  assorted, 
marked  and  bundled,  and  the  buffed  leather  is  ready  for  market. 

FLEXIBLE  SPLITS. 

After  splits  are  sorted  at  the  belt  knife  machine,  take  them 
to  the  drum  wheel.  Then  dissolve  half  a  bale  (a  bale  weighs 
about  250  pounds)  of  gambier,  or  the  same  proportion  of  ex- 
tract, in  a  barrel  of  water,  so  that  the  liquor  will  stand  at  80 
degrees  barkometer.  Now  bring  this  liquor  down  to  25  de- 
grees by  adding  six  pails  of  sweet  liquor,  12  degrees  barko- 
meter. Put  the  solution  in  the  mill,  and  let  the  splits  follow. 
Close  judgment  must  be  used  here.  If  the  splits  are  large,  mill 
28 


434 


THE  MANUFACTURE  OF  LEATHER. 


for  45  minutes.  Remove  and  leave  in  piles  for  say  12  hours. 
Then  throw  them  into  a  vat  containing  20  to  25-degree  liquor, 
and  leave  until  well-tanned,  say  three  or  four  days. 

Take  splits  out  and  put  in  wash-wheel  with  plenty  of  luke- 
warm water  through  the  axle  of  the  wheel.  Have  plugs  in 
wheel  so  that  impurities  may  be  washed  out.  The  wheeling 
should  occupy  20  to  30  minutes.  Now  take  50  gallons  of 
water,  to  which  add  four  pails  sumac  (about  20  pounds  of 
sumac  to  a  pail),  and  one  pound  of  alum.  Cook  to  the  boil- 
ing point.  Then  let  cool  to  1  io°  F.  The  splits  mean- 
while are  still  in  the  wheel,  and  to  them  should  be  added  from 
four  to  six  pails  of  the  sumac  liquor  just  made,  and  the  wheel 
run  for  about  30  minutes  at  16  revolutions  per  minute.  Re- 
move and  rinse  leather  in  clear  running  water. 

Now  heat  50  gallons  of  water  to  1200  F.,  into  which  put 
two  quarts  of  sugar  of  lead.  In  another  barrel  of  water  con- 
taining 50  gallons,  put  one  quart  of  vitriol.  Immerse  splits 
first  in  sugar  of  lead  solution  ;  then  in  vitriol  solution ;  then  in 
clear,  running  water.  The  leather  is  now  ready  to  be  sammied 
in  the  usual  way  like  satin  or  wax  splits. 

After  this  is  accomplished  and  the  leather  ready  to  set,  it 
should  be  put  under  a  setting-machine  and  well  set,  and  then 
rolled  down  fine  and  soft.  For  setting,  the  splits  should  be  as 
dry  as  possible.  For  instance,  100  pounds  dry  splits  should 
not  have  over  35  pounds  water  after  they  are  set  by  jack  or 
hand.  Now  make  the  following  :  Three  pounds  Irish  moss  and 
one-half  pound  soap,  and  cook  with  three  gallons  of  water  and 
strain.  The  mixture,  if  properly  attended  to,  will  resemble  a 
heavy  cream.  Set  this  on  one  side  and  apply  a  coat  of  it 
liberally  to  both  sides  of  the  splits.  Then  hang  up  in  a  warm 
room.  When  dry  take  down  and  leave  in  a  pile  to  press  for  a 
day  or  so.  Now  prepare  the  following:  Three  pounds  Irish 
moss,  one-half  pound  chip  soap,  half  pound  starch.  Dissolve 
this  in  cold  water,  say  four  gallons,  and  cook  well.  The  re- 
sult should  be  a  heavy  substance. 

Take  splits  to  jack.    Have  one  man  at  jack  and  one  man  to 


GRAIN  AND  SPLIT  LEATHER. 


435 


apply  the  mixture  to  flesh  side  first,  taking  the  splits  one  at  a 
time,  giving  liberal  dose  to  the  flesh  side,  same  time  running 
through  the  jack  in  wet  condition.  Be  sure  and  keep  one  split 
ahead  of  the  machine.  Hang  up  to  dry  them,  take  down  and 
go  over  grain  side  same  as  flesh.  The  leather  is  now  finished, 
and  is  ready  to  be  measured  and  bundled  for  the  market. 

Degras. — Where  we  speak  of  degras  in  this  chapter  we,  of 
course,  mean  that  which  is  obtained  in  England  and  Germany 
from  wool  grease,  not  the  French  degras  which  is  obtained 
from  the  oxidation  of  fish  oil  used  in  the  tannage  of  chamois 
leather. 


CHAPTER  XXIX. 


ENAMELED  LEATHER,  PATENT   LEATHER,   FURNITURE  OR  UP- 
HOLSTERING LEATHER,  REGALIA  LEATHER. 

Enameled  leather  is  grained  or  pebbled  so  as  to  give  it  a 
broken  surface.    Patent  leather  has  a  smooth  glossy  surface. 

The  steer  hides  employed  for  the  production  of  enameled 
and  patent  leather  to  be  used  for  carriage  tops,  and  also  those 
employed  for  furniture  or  upholstering  leathers,  are  the  largest 
and  finest  slaughter  hides  that  can  be  obtained,  practically 
free  from  blemishes.  The  largest  and  best  hides  are  selected 
from  those  which  are  purchased  in  the  markets  of  Chicago, 
Kansas  City,  St.  Louis  and  Omaha.  Hides  which  measure 
six  feet  eight  inches  across  the  brisket  and  over  are  taken. 
Cow  hides  which  measure  six  feet  four  inches  across  the 
brisket  and  over  are  taken  for  trimmings  and  furniture 
leathers.  Large  bull  hides,  measuring  six  feet  four  inches 
across  the  brisket,  are  used  for  patent  collar  leather,  and 
smaller  size  for  shoe  tippings. 

Sometimes  during  a  scarcity  of  hides  they  are  imported 
from  France,  Germany,  Switzerland  and  other  countries,  and 
Anglo-American  hides  are  brought  from  England ;  the  latter 
hides  being  those  of  animals  which  have  been  exported  from 
America  to  England  and  slaughtered  there. 

The  soaking,  unhairing  and  fleshing  of  the  hides  is  the  same 
as  has  been  described  for  other  varieties  of  leather.  The  lim- 
ing is  longer,  usually  for  ten  days.  If  the  limes  are  heated,  as 
some  tanners  employ  them,  they  remain  for  a  shorter  time, 
and  are  then  struck  on  the  beam  to  work  out  the  lime.  Then 
they  go  into  the  bate  of  pigeon  or  hen  manure,  which  by  some 
tanners  is  heated  to  about  ioo°  F.,  where  they  remain  for  five 


ENAMELED  LEATHER,  ETC. 


437 


or  six  hours,  care  being  observed  to  handle  them  up  five  or  six 
times  during  this  period.  Some  tanners  use  a  cold  bate,  in 
which  the  hides  are  allowed  to  remain  for  about  twenty-four 
hours.  They  then  go  on  the  beam  and  are  worked  over  very 
carefully  with  a  bate  stone.  When  they  have  been  properly 
worked  with  the  bate  stone  and  while  they  are  still  on  the 
beam,  they  are  further  worked  with  a  steel  worker  in  order  to 
free  the  hides  from  lime  and  dirt  as  much  as  is  possible.  They 
are  then  placed  in  a  perforated  wash  wheel  and  washed.  The 
wash  wheel  is  put  in  motion  and  a  two-inch  stream  of  cold 
water  run  continuously  on  the  hides  until  the  water  coming 
from  the  wheel  shows  no  signs  of  lime.  The  time  consumed 
in  this  washing  varies,  and  depends  upon  the  quantity  of  lime 
and  dirt  which  is  in  the  hides  when  they  are  thrown  into  the 
wheel.  Hides  treated  in  this  manner  will  go  into  the  liquors, 
practically  speaking,  perfectly  free  from  lime  and  grit,  which 
will  prepare  them  better  for  splitting  as  the  sand  and  dirt 
which  may  have  been  collected  in  the  flesh  will  have  been  re- 
moved by  the  washing  in  the  wheel.  This  washing  may  be 
done  in  two  or  three  minutes,  or  the  time  required  may  be 
longer,  depending  upon  circumstances.  As  soon  as  the  water 
runs  clear  from  the  wheel,  the  washing  is  complete  and  the 
motion  of  the  wheel  should  be  stopped.  This  washing  is  a 
very  important  step  in  the  manufacture  of  enameled  or  patent 
leather,  or  of  any  other  grade  of  leather,  as  hides  treated  in 
this  way  do  not  carry  any  lime  or  dirt  into  the  liquors,  and  the 
liquors  thereby  become  more  effective.  If  this  washing  is  not 
done,  it  will  be  necessary  to  place  the  hides  in  a  weak  sour 
liquor  containing  almost  no  tannin,  so  as  to  neutralize  the  lime 
that  may  be  left  in  the  hide. 

Care  should  be  taken  not  to  allow  the  wash  wheel  to  run  for 
too  long  a  time,  as  it  would  result  in  making  a  loose  and 
spongy  flank. 

After  they  have  been  properly  washed  the  hides  are  in  con- 
dition to  go  into  the  "  handlers"  or  "rockers"  to  be  properly 
swelled  for  the  reception  of  the  tanning  liquor. 


438 


THE  MANUFACTURE  OF  LEATHER. 


The  tanning  vats  used  in  some  tanneries  are  shown  in  Fig.  1 16. 

The  material  employed  by  some  tanners  for  tanning  the 
hides  is  a  mixture  of  oak  and  hemlock  bark,  making  what  is 
known  as  "  union  tannage."  Some  tanners  use  vats  having  a 
circular  bottom,  and  above  which  there  is  placed  a  revolving 
wheel  which  agitates  both  the  tanning  liquor  and  the  hides ; 


Fig.  i i  6. 


TANNING  VATS  IN  PATENT  LEATHER  FACTORY. 


there  being  usually  a  number  of  these  vats  placed  in  a  line,  as 
shown  in  Fig.  116.  The  wheels  are  worked  for  about  fifteen 
minutes  in  each  hour.  Other  tanners  use  "rockers"  where 
the  hides  are  stretched  out  and  hung  on  hooks,  the  hides  being 
rocked  three  or  four  times  a  day.  They  remain  in  the  rockers 
for  about  twelve  days,  the  time  depending  upon  the  strength  of 
the  liquor,  etc.,  the  longer  they  hang  the  plumper  and  firmer 
the  leather  will  be.  They  are  then  taken  out  and  put  in  a  large 


ENAMELED  LEATHER,  ETC. 


439 


power  press,  and  the  surplus  liquor  pressed  out.  They  are  then 
hung  up  and  partially  dried  or  "  sammied  "  to  prepare  them 
for  the  splitting  machines.  These  machines  are  known  as  the 
"Belt  Knife"  and  "Union." 

When  the  hides  are  in  proper  condition  they  are  split  from 
three  to  four  times,  three  times  being  the  average,  ist,  the 
burring  is  taken  off,  which  is  used  for  hat  sweats,  pocket  books, 
book  bindings,  etc.  2d,  shoe  tippings,  upholstering  leather, 
carriage  tops,  etc.  3d,  comes  the  middle  split,  which  is  used 
for  soft  dash  or  hard  dash,  and  if  a  very  heavy  hide,  a  flat 
split  or  "junior  winker"  used  by  harness  makers,  is  taken; 
fancy  splits,  enamel  splits,  inner  sole,  bag  leather,  shoe  splits, 
collar  leather  and  for  various  other  purposes.  4th,  comes  a 
slab  which  is  used  by  trunk  makers  and  collar  makers.  If  it  is 
very  light,  it  can  only  be  used  by  trunk  makers;  if  heavy,  by 
collar  makers.  5th  splits  are  very  rare,  unless  the  people  are 
making  very  light  splits,  and  light  splits  as  a  rule  have  very 
little  strength  on  account  of  having  very  little  fibre. 

The  hides  and  splits  after  leaving  the  splitting  machines  are 
re  tanned  in  japonica,  gambier,  hemlock,  quebracho,  canaigre, 
etc.,  as  circumstances  demand.  They  remain  in  the  re-tanning 
process  from  about  three  to  ten  days,  the  time  varying  in  differ- 
ent tanneries,  depending  upon  whether  the  tanner  uses  warm 
or  cold  liquors  and  how  well  the  hides  are  tanned  before  split- 
ting. The  tanner  may  sometimes  be  rushed  with  his  "  hand- 
lers "  or  "  rockers,"  thus  forcing  the  hides  to  be  split  in  a 
greener  state.  In  such  cases  it  will  be  necessary  to  give  the 
hides  a  longer  time  in  the  re  -tanning.  About  three  days  for  hides 
and  about  ten  days  for  splits  is  the  usual  time  in  cold  liquors,  de- 
pending upon  the  kind  of  leather  which  it  is  desired  to  produce. 
Warm  liquors  run  from  950  to  1000  F.,  cold  liquors  from  750  F. 
down.  The  re-tanning  is  done  in  boxes  which  measure  seven 
feet  and  six  inches  long,  by  five  feet  wide,  by  three  feet  six 
inches  deep  inside.  There  are  trays  set  over  the  boxes  on  one 
side  to  hold  the  hides  and  splits  as  they  are  handled  out  of  the 
liquor  each  day. 


440 


THE  MANUFACTURE  OF  LEATHER. 


The  heavy  leathers,  such  as  flap,  etc.,  require  longer  time, 
say  about  fifty  days,  and  are  twice  laid  away,  the  first  layer 
being  for  about  twenty-four  days,  and  the  second  for  about 
twenty-six  days.  This  treatment,  however,  is  arbitrary.  The 
hides  remain  in  the  last  layer  until  wanted,  it  may  be  for  three 
or  six  months,  depending  upon  the  demand  for  the  leather. 
It  is  a  good  place  to  preserve  the  hides  if  the  tanner  has  plenty 
of  spare  vats  and  little  storage  room. 

Then  the  hides  and  splits  are  placed  in  sumac  liquor  and  re- 
main for  one  day  ;  about  one-half  pound  of  sumac  being  used  for 
each  hide.  The  amount  of  sumac  employed  varies,  however, 
with  the  practice  in  various  tanneries.  Some  tanners  use  a  re- 
fined extract  of  sumac  which  takes  the  place  of  the  ground 
sumac  leaves,  saving  the  tanners  the  time  of  leaching,  also  sav- 
ing the  loss  that  often  occurs  from  souring  liquors. 

The  hides  and  splits  are  next  scoured  by  hand  on  a  table, 
which  accomplishes  two  things,  i.  c,  1st,  the  removal  of  the  ex- 
cess of  tanning  material,  dirt,  etc. ;  2d,  the  setting  out.  Then 
they  are  stuffed  with  various  mixtures  of  cod  oil,  degras,  linseed 
oil,  etc.  It  is  dangerous  to  use  either  cod  oil  or  degras  unless 
a  strictly  pure  article  can  be  had,  as  a  poor  quality  of  cod  oil 
or  degras  made  from  it  will  cause  the  leather  to  gum  on  the 
surface  and  to  stick  together  and  stain  in  spots.  If  there  be 
any  question  about  the  quality  of  the  cod  oil  and  degras,  it 
will  be  better  to  use  only  either  raw  or  boiled  linseed  oil. 

A  stuffing  which  has  been  found  to  be  very  satisfactory  in 
practice  is  made  as  follows: 

Dry  white  lead   30  pounds. 

Litharge   30  pounds. 

Raw  linseed  oil   50  gallons. 

The  dry  white  lead  and  litharge  are  each  mixed  with  about 
ten  gallons  of  raw  linseed  oil,  and  these  two  mixtures  of  twenty 
gallons  are  poured  into  the  kettle  and  thoroughly  stirred  be- 
fore it  goes  upon  the  fire.  The  stirring  is  done  with  the  idea 
of  preventing  the  white  lead  and  litharge  from  settling  in  the 


ENAMELED  LEATHER,  ETC. 


441 


bottom  of  the  kettle.  This  mixture  of  white  lead,  litharge  and 
linseed  oil  is  boiled  together  for  six  or  eight  hours  and  carried 
to  about  4000  F.,  or  until  it  is  reduced  to  the  consistency 
of  syrup.  The  mixture  when  cold  is  reduced  with  naphtha, 
say  fifty  gallons  of  naphtha  to  fifty  gallons  of  oil,  or  it  can  be 
reduced  to  any  required  body  and  applied  to  the  hides  or  splits. 

After  they  come  from  the  scouring  and  stuffing  tables,  the 
pieces,  hides,  splits  and  buffings  are  tacked  on  stretching  frames 
and  stretched,  and  allowed  to  become  thoroughly  dry. 

A  good  frame  for  stretching  leather  is  shown  in  Figs.  1 17  to 
121,  and  is  the  invention  of  Charles  P.  Oliver  and  Theodore 
P.  Howell,  of  Newark,  N.  J. 

This  device  possesses  the  merit  of  unusual  simplicity  and 
cheapness  of  construction,  and  also  is  susceptible  of  operation 
without  removing  the  frame  from  its  pendent  position  from  the 
supporting-bars. 

Fig.  117  is  a  representation  of  a  top  view  ol  Oliver  and 
Howell's  Machine.  Fig.  1  18  is  a  vertical  transverse  section  of 
the  same.    Figs.  119,  120  and  121  are  details  of  the  same. 

A  represents  the  upper  and  B  the  lower  cross-bar  of  the 
stretching-frame,  and  C  indicates  the  sides.  On  the  front  sides 
of  the  bar  C,  or  upon  the  sides  of  such  bars,  are  affixed  per- 
forated plates,  marked  a.  These  perforated  plates  are  adapted 
for  use  upon  wooden  upright  bars;  but  in  case  such  bars  be 
made  of  metal,  the  plates  may  be  dispensed  with,  and  the 
cross-bars  themselves  be  perforated.  The  cross-bar  A  is  con- 
structed with  a  rounded  upper  surface,  to  adapt  it  for  holding 
the  centre  of  the  hide,  inasmuch  as  this  apparatus  is  designed 
for  attaching  both  flanks  or  sides  of  the  hide  to  the  sliding  bar 
D.  The  letter  D  represents  the  sliding  or  stretching  bar, 
which  is  arranged  with  reference  to  the  bars  A  and  C  in  the 
manner  shown.  The  letter  c  indicates  the  short  arm  of  a  joint 
attached  to  the  sliding  bar  D,  and  /  indicates  the  long  arm 
thereof  attached  to  the  bar  B,  each  connection  being  made 
with  a  suitable  pivot-pin  or  hinge.  These  two  arms  of  the 
joint  are  united  by  a  tongue-and-groove  joint,  as  shown  in  Fig. 


442 


THE  MANUFACTURE  OF  LEATHER. 


1 1 8.  It  will  be  observed  that  the  end  of  the  sliding  bar  D  is 
slotted  to  provide  for  holding  the  forearm  of  the  joint  and  allow 
the  movements  thereof.    The  letter  y  indicates  a  quadrangular 

Fig.  i  1 7. 


C 


T5*n 


c 


WE 


Fig.  118. 


a         Ell  | 

Fig.  120. 


Fig.  121. 


wrist  firmly  attached  to  the  short  arm  of  the  joint.  It  is  pre- 
ferable to  cast  this  arm  and  wrist  in  one  piece  of  metal.  The 
letter  H  represents  a  wrench,  the  head  of  which  is  adapted  to 
fit  upon  the  wrist  y. 


ENAMELED  LEATHER,  ETC. 


443 


To  operate  this  device,  tack  the  moist  hide  to  the  sides  of 
bar  D,  allowing  the  centre  thereof  to  rest  upon  the  oval  upper 
surface  of  bar  A,  and  place  the  wrench  head  upon  the  wrist  y. 
Then  turn  the  wrench  downward,  bringing  the  two  arms  of  the 
joint  toward  or  beyond  a  right  angle,  thereby  increasing  the 
distance  between  the  bars  A  and  D.  When  the  skin  is  suffi- 
ciently stretched,  place  a  pin  above  the  bar  D  in  one  of  the 
apertures  of  the  perforated  plate,  and  permit  the  skin  to  dry,  or 
be  manipulated,  as  the  operator  may  see  fit. 

The  dry  room  is  heated  by  steam  and  a  ventilating  fan  draws 
off  the  moisture  ;  the  drying  usually  requiring  two  or  three  days. 
The  hides  and  splits  are  then  taken  from  the  stretching  frame 
and  are  passed  through  a  pin-block  machine,  to  give  them  a 
preliminary  softening,  and  are  next  taken  to  the  table  and 
boarded  by  hand  to  complete  the  softening.  The  softening 
table  is  covered  with  a  split,  which  is  tacked  on  in  the  wet  state 
so  as  to  dry  even  and  taut. 

After  the  hides,  splits  and  buffings  are  softened  they  go  to 
the  "  patcher,"  whose  business  it  is  to  patch  up  the  pieces  by 
the  putting  on  of  a  patch  with  glue  to  prevent  the  enamel  com- 
position which  is  later  on  to  be  applied  from  running  through 
and  staining  the  under-side  of  the  piece.  Then  the  hides,  splits 
and  buffings  go  to  the  table  of  the  sorter,  who  classifies  them 
into  the  different  grades  as  to  quality,  size  and  substance.  The 
buffings  are  graded  as  to  the  degree  of  imperfections,  such  as 
horn  scratches,  rough  grain  brands,  grub  holes,  salt  stains  and 
substance,  making  about  five  selections.  The  buffings  are 
further  graded  as  to  the  manner  in  which  they  split,  viz.,  the 
"  Belt  Knife  "  and  "  Union."  The  "  Belt-Knife"  buffings  have 
the  head  and  butt  on  them.  The  "Union"  buffings  have 
either  the  head  or  butt  missing.  The  hides  are  divided  into 
two  classes,  hand-buffed  and  machine-buffed.  The  hand-buffed 
hides  bring  the  best  price,  as  the  buffing  is  sacrificed  and  only 
the  best  hides  are  selected  for  this  class. 

The  hand-buffed  hides  make  the  following  grades,  viz. :  grain 
dash,  landau,  calache,  top  hides,  upholstering,  trimming,  shoe 
enamel,  shoe  tipping  and  binding  leather. 


444 


THE  MANUFACTURE  OF  LEATHER. 


The  machine-buffed  hides  make  the  following  grades,  viz. : 
grain  dash,  top  hides,  upholstering,  trimming  and  binding 
leather. 

The  splits  make  the  following  kinds  of  leather,  viz. :  skirting, 
hard  dash,  soft  dash,  black  and  fancy  enameled  splits. 

The  buffings  which  have  been  selected  for  japanning  are  di- 
vided into  three  classes ;  the  best  grade  going  into  enameled 
buffings,  the  next  grade  into  fancy  colored  buffings,  and  the 
last  grade  into  patent  or  black  buffings.  The  buffings  which 
are  not  required  for  japanning  are  sold  in  the  russet  for  mak- 
ing stained  buffings,  which  are  used  for  book  bindings,  pocket- 
books,  ladies'  hand-bags,  etc. 

The  hides,  splits  and  buffings  which  have  been  selected  for 
enameling  are  next  toggled,  stretched  and  tacked  on  a  frame 
with  ten-ounce  tacks.  The  hide  frames  are  about  nine  feet  by 
ten  and  one-half  feet  outside  measurements,  and  are  made  of 
seven-eighths  inch  stuff,  four  and  one-half  inches  wide.  The 
split  frames  are  about  nine  by  nine  feet,  made  of  the  same 
material.  For  japanning  side  leather  the  frames  are  about  four 
and  one-half  feet  by  nine  feet,  made  of  one  and  one-quarter 
inch  stuff,  five  inches  wide. 

BLACK    ENAMELED  TOP  LEATHER   SUCH  AS  IS  USED  FOR  BUGGY  AND  CAR- 
RIAGE TOPS. 

The  hides  next  receive  a  heavy  coat  of  daub,  which  is  made 
of  raw  linseed  oil  boiled  to  a  jelly.  The  boiling  usually  re- 
quires about  twenty-four  hours,  which  time  includes  about  five 
hours  allowed  for  the  addition  of  naphtha,  which  is  hereafter 
described.  The  time  is  usually  spread  over  two  days,  twelve 
hours  being  consumed  each  day.  The  kettle  in  which  the  oil 
is  boiled  should  be  twice  the  capacity  of  the  oil  to  be  boiled  at 
one  time.  The  kettle  should  be  portable  and  mounted  upon  a 
truck,  so  as  to  wheel  it  off  the  fire  when  the  temperature  be- 
comes too  high.  There  should  be  a  lug  or  flange  for  holding 
thermometer  in  kettle.  The  boiling  is  done  over  a  coke  fire 
similar  to  the  fires  in  use  in  an  ordinary  varnish  factory.  The 


ENAMELED  LEATHER,  ETC. 


445 


oil  is  continually  stirred  from  start  to  finish  with  an  iron  paddle 
about  eight  feet  long,  or  of  any  suitable  size,  with  holes  made 
through  the  paddle  portion,  which  is  about  three-sixteenths  of 
an  inch  thick,  to  prevent  the  throwing  of  the  oil  out  of  the 
kettle. 

The  oil  is  carried  gradually  to  about  5800  F.  the  first  twelve 
hours,  and  is  then  lowered  to  about  4000  F.  before  leaving 
work  for  the  day.  The  next  day  the  temperature  of  the  oil  is 
again  gradually  increased  to  from  580°  F.  to  6io°  F.,  depend- 
ing upon  the  nature  of  the  oil,  the  weather,  etc.  Some  oils 
will  cook  with  less  heat  than  others.  When  the  oil  is  cooked 
to  the  consistency  of  a  jelly  on  the  second  day,  it  is  taken  off 
the  fire  and  cooled  down  to  about  4000  F.,  and  naphtha  is 
added  in  the  proportion  of  one  and  one-third  gallons  of  naphtha 
to  the  gallon  of  oil.  Say  we  are  boiling  seventy-five  gallons  of 
oil  and  it  is  ready  to  receive  the  naphtha  ;  the  naphtha  is  added, 
twenty-five  gallons,  to  reduce  the  temperature  of  the  oil,  which 
is  slowly  stirred  in,  and  when  this  twenty-five  gallons  has  dis- 
appeared, twenty-five  gallons  more  of  naphtha  are  added,  under 
constant  stirring,  so  as  to  break  up  the  composition  and  allow 
the  naphtha  to  penetrate  it,  and  this  is  continued  until  about 
one  hundred  gallons  of  naphtha  are  added,  only  twenty-five  gal- 
lons at  a  time  being  put  in.  The  more  rapidly  the  naphtha  is 
added  and  the  composition  stirred,  the  better.  The  fire  used 
for  cooking  the  oil  must  be  put  out,  every  spark  of  it,  before 
the  naphtha  is  added.  The  brick-work  of  the  furnace  is  flooded 
with  water,  so  as  to  prevent  the  gas  which  comes  from  the 
naphtha  from  striking  the  hot  bricks  and  thereby  causing  an 
explosion  of  all  the  naphtha.  When  you  desire  to  make  a 
foundation  for  a  dark  color,  such  as  black  enamel,  soft  dash, 
hard  dash  and  black  buffings,  add  one  pound  of  lamp-black 
of  the  best  quality  free  from  grease  to  four  gallons  of  the 
composition  just  described,  which  is  known  technically  as 
"sweet-meats."  It  does  not  take  the  name  of  daub  until  the 
lamp-black  is  put  in. 

The  lamp-black  is  added  under  constant  stirring.    In  large 


446  THE  MANUFACTURE  OF  LEATHER. 

works,  such  as  the  American  Oak  Leather  Company  of  Cincin- 
nati, Ohio,  the  stirring  is  done  in  a  mill  built  for  the  purpose, 
which  holds  about  sixty  gallons.  It  has  two  upright  pieces  of 
iron  or  blades  bolted  to  the  bottom  and  extending  to  the  top  of 
the  mill.  The  dasher  which  revolves  at  the  top  of  the  mill  has 
four  blades  bolted  to  it  on  one  side  and  two  blades  on  the  other, 
so  arranged  that  the  upright  blades  pass  between  the  revolving 
blades.  The  mill  has  an  opening  at  the  bottom  through  which 
the  daub  is  drawn.  The  mill  is  driven  by  power  and  makes 
about  sixty  revolutions  a  minute.  The  daub  is  ready  to  apply 
to  the  leather  as  soon  as  it  comes  from  the  mill.  This  daub  is 
applied  to  the  hide  as  a  filler  and  is  put  on  with  a  steel  slicker, 
the  blade  of  which  measures  ten  and  one-half  inches  long  by 
two  and  five-eighths  inches  deep,  and  nearly  one-eighth  of  an 
inch  thick,  having  rounded  corners  and  a  knitting-needle  edge. 
The  daub  must  be  worked  in  thoroughly  and  the  excess  scraped 
off  with  a  slicker,  care  being  observed  in  the  scraping  not  to 
scratch  the  hide.  The  hide  is  then  exposed  to  the  sunshine  or 
air  until  the  daub  coat  is  thoroughly  dry.  When  dry  the  hide 
is  given  a  second  coat  of  the  same  composition.  Usually  the 
second  coat  is  put  on  the  next  day,  and  it  is  then  run  into  the 
oven  (see  Fig.  122)  to  dry,  remaining  from  ten  to  twelve 
hours  at  a  temperature  of  from  1  io°  F.  to  1200  F.  The  hide 
then  receives  a  slicker  coat,  which  is  linseed  oil  boiled  to  about 
the  consistency  of  New  Orleans  molasses.  This  slicker  coat  is 
put  on  with  a  smaller  and  thinner  slicker  than  that  used  for  the 
daub,  and  is  a  scant  one-sixteenth  of  an  inch  in  thickness. 
After  the  slicker  coat  is  dry,  which  usually  requires  about 
twelve  hours  in  the  oven,  it  is  rubbed  with  a  flat  piece  of  pumice 
stone  to  make  a  smooth  surface.  The  hides  next  receive  a 
coat  of  enameled  varnish,  which  is  made  of  linseed  oil  and 
Chinese  blue,  boiled  down  to  the  same  consistency  as  the 
slicker  varnish.  It  is  boiled  for  about  eight  hours,  and  is  grad- 
ually carried  to  about  5600  F.,  being  stirred  all  the  time.  This 
varnish  is  reduced  with  naphtha.  After  the  first  coat  of  varnish 
is  put  on,  the  hide  is  again  placed  in  the  oven  and  thoroughly 


ENAMELED  LEATHER,  ETC. 


447 


dried,  which  usually  requires  about  ten  hours.  It  is  then  taken 
out  and  pumiced,  and  receives  the  final  or  finishing  coat,  and  is 
again  placed  in  the  oven  and  dried  at  about  1400  F.  The  hide 
is  next  exposed  to  the  sun  and  air  to  remove  the  sticky  surface. 
The  length  of  exposure  varies,  running  from  three  to  ten  hours. 
The  hide  is  then  taken  from  the  frame,  and  hung  in  a  damp 


Fig.  122. 


DRYING  OVEN   IN  PATENT  LEATHER  FACTORY. 


room  for  twenty-four  hours,  and  allowed  to  regain  the  natural 
moisture  lost  in  the  japanning  process.  The  edges  are  then 
trimmed  to  remove  the  tack  marks,  toggle  holes  and  varnish. 
It  is  then  boarded  by  hand  to  raise  the  grain  after  which  it  is 
measured,  and  is  ready  for  the  market. 

SMOOTH  FINISHED  PATENT  LEATHER. 

The  split  receives  three  coats  of  daub.  The  last  coat  of 
daub  when  dry  is  pumiced.    Then  it  receives  a  coat  of  black 


448 


THE  MANUFACTURE  OF  LEATHER. 


varnish,  which  when  dry  is  also  pumiced.  The  second  coat  of 
black  varnish  is  then  put  on  and  dried,  and  after  the  drying  is 
completed  this  coat  of  varnish  is  again  pumiced.  The  daub 
used  for  splits  is  nearly  the  same  as  for  the  hides,  but  the  boil- 
ing of  the  oil  does  not  require  so  long  a  time,  about  twenty 
hours  being  sufficient. 

The  black  varnish  is  made  of  linseed  oil  and  raw  umber 
boiled  from  eight  to  ten  hours  at  a  temperature  of  from 
500°  to  5800  F.  being  stirred  continually.  The  cooking  is 
known  to  be  done  or  finished  when  a  sample  of  the  varnish 
taken  from  the  pot  and  cooled  can  be  stretched  into  a  thread 
between  the  thumb  and  first  finger.  When  the  varnish  is 
boiled  to  this  stage  it  is  taken  off  the  fire  and  cooled  down 
to  about  350^  F.,  and  lamp-black  of  the  best  quality,  free 
from  grease,  is  gradually  added  under  careful  and  continuous 
stirring  until  it  becomes  one  body.  The  lamp-black  is  added 
in  the  proportion  of  about  one- fourth  pound  to  a  gallon  of  oil, 
measured  before  boiling.  This  black  varnish  is  then  reduced 
with  naphtha  until  it  will  flow  freely  under  the  brush,  usually 
about  one  and  one-fourth  gallons  of  naphtha  to  one  gallon 
of  the  raw  linseed  oil  measured  before  boiling.  The  split  next 
receives  three  coats  of  finishing  varnish  as  follows :  The 
first  coat  is  flowed  on  with  a  brush  and  dried  in  the  oven 
at  about  1700  F.  for  from  ten  to  fifteen  hours,  or  until  it  is 
thoroughly  dry ;  care  being  always  observed  not  to  get  it 
too  dry.  It  is  pumiced  and  receives  the  second  coat  of  varnish, 
which  is  again  dried  at  about  1700  F.  for  ten  to  fifteen  hours, 
the  same  care  being  observed  as  in  the  first  drying.  It  is  then 
very  lightly  pumiced  with  a  very  fine,  smooth  stone.  It  is  then 
perfectly  cleansed  of  all  dirt,  dust  and  grit.  The  split,  in  fact, 
receives  two  cleansings :  1st,  the  dry  dusting,  which  is  done 
with  a  dry  sweep ;  2nd,  the  cleansing,  which  is  done  with  a  wet 
sweep. 

The  split  is  now  ready  for  the  final  coat  of  varnish,  which  is 
flowed  on  very  carefully,  and  is  then  put  in  the  oven  and  dried 
at  a  temperature  of  about  1700  F.  and  remains  usually  for  about 


ENAMELED  LEATHER,  ETC. 


449 


forty-eight  hours,  judgment  being  used  as  to  the  degree  of  heat, 
which  is  intended  to  bake  or  unite  all  the  compositions  applied 
to  one  body.  The  finishing  varnish,  three  coats  of  which  are 
applied,  is  made  of  linseed  oil  and  Chinese  blue.  From  two  to 
six  ounces  of  Chinese  blue  is  added  to  the  gallon  of  oil,  and 
this  is  boiled  to  about  the  consistency  of  the  black  varnish. 
The  composition  is  stirred  continually  and  is  boiled  for  eight 
or  ten  hours.  The  composition  should  cook  at  5800  F.  It 
should  then  be  dipped  over  into  a  reducing  pan,  which  must  be 
outside  of  the  boiling-room,  and  is  allowed  to  cool  over  night. 
The  next  day  it  is  reduced  or  thinned  with  one  gallon  of  naph- 
tha to  each  gallon  of  oil.  The  naphtha  is  added  gradually 
under  constant  and  continual  stirring.  This  varnish  is  stored 
in  a  room  which  has  about  700  F.  for  its  temperature,  and  re- 
mains for  about  six  weeks  before  using.  After  the  split  has 
been  exposed  to  the  heat  of  the  oven  for  about  forty-eight 
hours,  it  is  taken  out  and  cut  off  the  frame,  trimmed  and  meas- 
ured ready  for  the  market. 

PLAIN  BLACK  BUFFINGS. 

The  buffing  receives  one  coat  of  black  daub  the  same  as  the 
hide,  two  coats  of  black  varnish  and  two  coats  of  finishing  var- 
nish. The  drying  must  be  done  at  about  one-third  less  tem- 
perature than  for  splits.  Care  should  be  taken  not  to  dry  too 
much.  The  buffing  should  be  exposed  to  the  sun  or  air  on  the 
finishing  coat.  It  is  then  cut  from  the  frame,  trimmed  and 
measured  ready  for  the  market. 

FURNITURE  OR  UPHOLSTERING  LEATHER. 

The  finishing  of  furniture  leather  for  the  first  three  coats  of 

daub  is  the  same  as  for  black  enameled  top  leather  previously 

described.    Then  it  is  painted  of  any  desired  shade.  The 

number  of  coats  depends  upon  the  shade  required.  Furniture 

leather  is  not  varnished.    It  is  dried  at  about  1200  F.  The 

colors  can  either  be  bought  ground  in  oil  or  dry,  the  grinding 

being  done  under  your  own  supervision  and  with  oil  especially 

purchased  for  the  purpose. 
29 


45© 


THE  MANUFACTURE  OF  LEATHER. 


REGALIA  LEATHER. 

Regalia  leather  is  made  from  about  the  same  selection  of 
hides  as  is  the  furniture  and  upholstering  leather.  The  usual 
colors  are  red,  white,  blue,  orange,  lemon  and  maroon,  but  any 
color  that  is  desired  can  be  produced.  Regalia  leather  receives 
the  same  number  of  coats  as  furniture  or  upholstering  leather, 
and  is  dried  in  the  oven  at  about  the  same  temperature.  But 
this  daub  has  no  lamp-black  in  it ;  it  is  in  fact  the  "  sweet-meats  " 
already  referred  to  reduced  to  the  substance  of  daub.  It  is 
pumiced  on  the  last  daub  coat,  and  it  receives  as  many  coats 
of  color  as  are  necessary  to  produce  the  shade  desired.  The 
colors  are  mixed  with  a  fine  clear  varnish,  free  from  gum ;  but 
the  last  coat  is  clear  varnish.  Care  should  be  used  to  pur- 
chase the  very  best  colors  that  are  made.  Buy  them  dried,  and 
grind  them  in  oil  yourself.  The  oil  used  is  what  is  called  the 
clarified  boiled  linseed  oil.  We  have  the  formula  of  a  varnish 
which  is  used  for  making  regalia  leather  and  all  delicate  colors. 
This  varnish  is  free  from  gum,  and  leather  coated  with  it  will  not 
break  or  stick.  It  is  the  most  valuable  varnish  for  the  pur- 
pose which  we  have  ever  seen.  We  are  not  at  libeity,  how- 
ever, to  make  public  the  formula  of  this  varnish,  as  there  are 
other  parties  interested  with  us  in  its  ownership. 

NOTES. 

The  finishing  room  should  be  kept  clear  of  dirt  of  all  kinds. 
There  should  be  no  draft.  Ventilation  should  be  through  the 
roof.  No  rags  and  no  clothes  should  be  allowed  in  the  room. 
The  men  when  finishing  wear  no  clothes  except  trousers  and 
shoes. 

Naphtha  is  used  as  a  reducing  agent  for  the  compositions 
instead  of  turpentine,  because  it  is  cheaper,  costing  only  about 
one-sixth  as  much. 

Compositions  which  are  intended  to  be  aged  are,  however, 
better  produced  with  turpentine,  as  naphtha  will  evaporate  too 
quickly. 

The  thermometer  used  for  boiling  the  oil  can  be  bought  from 


ENAMELED  LEATHER,  ETC. 


451 


the  Hohmann  &  Mann  Manufacturing  Co.,  Plymouth  and  Jay 
Streets,  Brooklyn,  N.  Y. 

The  sweep  and  the  round  varnish  brush  used  for  flowing  on 
both  the  black  varnish  and  the  finishing  varnish,  which  is  a 
seven-inch  Russia  bristle,  and  the  flat  brush  used  for  painting 
furniture  leather,  can  be  purchased  from  Dixon  &  Ripple, 
Newark,  N.  J.  The  slickers  can  be  bought  from  Richardson, 
Newark,  N.  J.  H.  L.  Pope  &  Co.,  Dayton,  Ohio,  make  a  good 
grade  of  linseed  oil  by  the  old  process,  which  is  much  used  for 
manufacturing  enameled  and  patent  leather. 

A  GOOD  WAY  TO  OPEN  ENAMELED  AND  PATENT  LEATHER  WHICH  IS  STUCK 

TOGETHER. 

Put  the  leather  out  on  the  grass  before  sunrise,  while  the  dew 
is  on  the  grass.  Let  it  lie  until  the  sun  warms  it  through,  and 
then  strip  it.  This  method,  of  course,  can  only  be  used  in 
warm  weather. 

PRESERVING  THE  GLOSS  ON  PATENT  LEATHER. 

The  following  is  a  French  recipe  for  preserving  the  gloss  of 
patent  leather:  Melt  pure  wax  over  a  water-bath,  place  on  a 
moderate  coal  fire,  add  first  some  olive  oil,  then  some  lard, 
and  mix  intimately  by  stirring;  next  add  some  oil  of  turpen- 
tine, and  finally  some  oil  of  lavender,  fill  the  resulting  paste  into 
boxes,  where,  on  solidifying,  the  necessary  consistency  will  be 
acquired.  To  restore  the  gloss  to  the  leather  apply  a  little  of 
the  paste  and  rub  with  a  linen  rag.  This  will  keep  the  leather 
soft  and  prevent  cracking. 

RENEWING  THE  SURFACE  OF  JAPANNED  LEATHER. 

In  1863  Wm.  Hoey  patented  in  England  the  following  com- 
pound for  renewing  the  surface  of  japanned  leather:  Two 
ounces  of  paraffin,  or  rock  oil,  or  a  mixture  of  both  in  any 
proportion,  to  which  are  added  one-quarter  of  a  drachm  of  oil 
of  lavender,  one-quarter  of  a  drachm  of  citronel  essence,  and 
one-half  ounce  of  spirits  of  ammonia.  The  mixture  is  applied 
lightly  to  the  surface  of  the  leather. 


452 


THE  MANUFACTURE  OF  LEATHER. 


PREPARING  THE    CUT   SURFACE   OF   SPLIT   LEATHER   FOR  MANUFACTURING 
JAPANNED  OR  ENAMELED  LEATHER. 

The  common  way  of  buffing  the  hide  or  preparing  it  for 
japanning  or  enameling  is  either  by  shaving  off  the  inequalities 
with  a  currying-knife,  or  by  taking  off  a  light  buffing  with  the 
regular  splitting  machine.  This  light  buffing,  when  finished,  is 
of  little  value,  bringing  from  one  to  three  dollars.  The  way 
japanned  or  enameled  leather  is  often  treated  is  by  applying  all 
the  coats  of  the  composition  to  the  leather  after  being  tanned, 
and  when  perfectly  dry  on  the  frames.  The  naphtha  or  turpen- 
tine in  the  composition  is  then  absorbed  by  the  dry  leather, 
and  it  becomes  dry  and  harsh  ;  but  by  applying  the  first  coat 
of  the  composition  when  the  leather  is  wet  and  the  pores  are 
filled  with  tan-ooze,  the  naphtha  or  turpentine  evaporates  be- 
fore the  leather  becomes  dry,  and  is  not  absorbed  by  it,  and 
the  leather  is  left  soft  and  flexible  and  more  easily  worked. 

If  a  heavy  buffing  be  taken  off,  it  leaves  the  surface  fibrous 
and  coarse,  and  it  is  necessary  to  have  a  smooth  surface  to 
finish  on — that  is,  to  japan  or  enamel. 

Stephen  J.  Patterson,  of  Bridgeport,  Conn.,  in  1883  patented 
the  following  method  for  forming  an  artificial  grain  on  the  hide 
after  it  has  been  buffed  or  split  with  a  regular  splitting 
machine. 

This  process  of  treatment  applies  equally  well  to  light  buff- 
ings or  splits,  but  is  especially  adapted  to  heavy  ones  by 
largely  increasing  their  value. 

Patterson's  improvement  is  as  follows :  When  the  split  hide 
comes  from  the  tan-liquor  after  the  tanning  operation  is  com- 
pleted, it  is  slicked  out  on  a  table  and  a  light  coat  of  oil  spread 
over  the  surface  with  a  sponge  or  soft  brush.  Then  it  is  tacked 
on  a  frame,  and  while  still  wet  the  fibre  or  nap  of  the  freshly- 
cut  surface  is  brushed  down  smooth  in  one  direction  with  a 
flexible  bristle  brush  (like  a  shoe-blacking  brush,  but  larger), 
which  simply  gives  direction  to  the  fibre  or  nap;  and  then 
there  is  applied,  while  the  hide  is  still  wet,  with  the  same  brush 
or  with  a  sponge,  rubbing  in  the  same  direction,  a  coat  of  com- 


ENAMELED  LEATHER,  ETC. 


453 


position  made  from  linseed  oil  boiled  down  to  a  jelly  and  re- 
duced with  naphtha  or  turpentine  to  the  proper  consistency. 
After  this  application  repeat  the  brushing  operation  as  before. 
The  hide  is  now  left  to  dry,  and  when  dry  the  composition 
holds  the  fibre  or  nap  in  place,  and  the  leather  has  a  smooth 
surface  to  japan  or  enamel.  When  dry  it  is  finished  the  same 
as  other  japanned  or  enameled  leather.  The  hide  is  not 
dubbed  with  a  mixture  of  cod  oil  and  tallow  or  other  grease,  as 
in  the  ordinary  method  of  preparing  heavy  leather.  For  shoes 
and  harness  only  a  light  coat  of  oil  is  applied  as  stated.  It  is 
buffed  or  split  with  the  splitting-machine  when  about  one-third 
tanned. 

For  treatment  by  this  process,  Mr.  Patterson  takes  off  a 
heavy  buffing  with  the  largest  size  improved  "  Union  Splitting- 
Machine,"  making  a  buffing  about  three-fourths  the  size  of  the 
hide.  This  is  thick  enough  to  japan  for  shoe  leather  or  similar 
purposes,  and  will  bring  from  four  to  eight  dollars  when  fin- 
ished. The  extra  expense  will  not  exceed  one  per  cent,  of  the 
cost  of  the  hide. 

JAPANNED  LEATHER  IN  IMITATION  OF  ALLIGATOR  SKIN. 

The  object  of  this  process,  which  was  patented  by  Franklin 
S.  Merritt,  of  Boston,  Mass.,  in  1 871,  is  to  produce  japanned 
leather  in  imitation  of  alligator  skin. 

The  leather  is  prepared  by  the  ordinary  process  of  currying 
for  patent  or  enameled  leather.  Afterward  it  is  coated  with  a 
composition  of  linseed  oil  boiled  with  driers,  viz.,  litharge,  burnt 
or  raw  umber,  sugar  of  lead,  sulphate  of  zinc,  Prussian  or  Chi- 
nese blue,  mixed  with  naphtha,  benzine,  spirits  of  turpentine,  or 
camphine,  with  sufficient  lamp  or  ivory-black  to  give  it  color- 
ing. 

The  leather,  after  being  coated  with  several  layers  of  the 
composition,  each  being  dried  before  the  next  is  applied,  is 
rubbed  with  pumice-stone  to  give  a  smooth  surface  to  the  coat- 
ing. Finally  the  last  layer  is  applied  and  dried  without  rubbing 
with  pumice-stone,  the  whole  making,  thus  far,  what  is  usually 


454 


THE  MANUFACTURE  OF  LEATHER. 


called  "patent  or  enameled  leather."  The  leather  in  this  state 
is  next  wet  sufficiently  to  soften  it  to  admit  of  its  receiving  and 
retaining  the  impression  of  the  die  or  rollers.  Next  the  sheet 
of  leather  is  passed  between  rollers  or  dies,  or  compressed  by 
the  same,  so  as  to  emboss  it  with  the  required  figure  or  series 
of  convexities.  Next  it  should  be  softened  while  wet  by 
"  boarding,"  or  by  any  other  mode  of  effecting  such  as  usually 
adopted  by  leather  dressers,  and  then  dried. 

Fig.  123. 


Figure  123  represents  a  face  view,  and  Figure  124  a  section 
of  a  piece  of  leather  made  as  described. 

When  finished  it  may  be  used  for  many  purposes  in  the  arts, 
particularly  in  the  manufacture  of  hand-satchels,  shoes,  etc. 

LINSEED  OIL. 

Linseed  oil,  which  enters  so  largely  into  the  "sweet-meats," 
and  daub  for  enameled  and  patent  leather,  is  obtained  from 
seeds  of  Linum  iisitatissimnm  (Linn).  They  contain  30  to  35 
per  cent,  of  oil,  26  per  cent,  of  which  can  be  obtained. 


ENAMELED  LEATHER,  ETC. 


455 


Winter  Flax. 


Spring  Flax. 


Oil 


35.20  per  cent. 
53.00  " 

315  " 
8.65  " 


31.60  per  cent. 
57-40  " 

3.20  " 

7.80  " 


Organic  Substance* 

Ash  

Water  


100.00  per  cent. 


100.00  per  cent. 
24.00  " 


*  Protein  substance  therein  ....  22.10 


The  oil  is  obtained  by  either  of  the  three  following  pro- 
cesses : 

Cold  Drawn  Oil. — The  seeds  are  crushed,  ground  or  bruised, 
and  expressed  without  heat.  This  is  considered  the  best  oil, 
and  in  Russia  and  some  parts  of  Germany  is  used  as  a  table 
oil  and  for  baking.  By  this  process  the  seeds  yield  from  20  to 
21  per  cent,  of  oil. 

Ordinary  Linseed  Oil. — It  is  prepared  in  the  same  manner 
as  above,  but  with  the  assistance  of  heat,  which  gives  it  a  disa- 
greeable taste.  The  yield  is  from  27  to  28  per  cent.  It  is 
used  for  technical  purposes. 

By  Extraction. — With  a  yield  of  32  to  33  per  cent.  Seeds 
two  to  six  months  old  are  generally  used,  as  the  oil  expressed 
from  fresh  seeds  is  viscous  and  turbid.  The  cold-drawn  oil  is 
golden  yellow,  and  has  a  peculiar  but  not  disagreeable  taste 
and  odor.  The  hot  pressed  oil  is  amber-colored  or  brown- 
yellow,  and  has  an  acrid  taste,  due  to  traces  of  volatile  fatty 
acids,  such  as  butyric,  valerianic  and  caproic  acids. 

Linseed  oil  is  somewhat  thickly  fluid,  and,  as  it  belongs  to 
the  drying  oils,  very  quickly  absorbs  oxygen  from  the  air,  be- 
comes lighter  in  color,  rancid,  finally  entirely  thickly  fluid,  and 
dries.  Its  specific  gravity  is  0.9375  at  500  F. ;  0.9463  at 
53. 50  F. ;  O.9350  at  590  F. ;  0.9325  at  68°  F. ;  and  0.9300  at 
77°  F.  At  590  F.,  the  oil  is  9.7  times  more  thickly  fluid  than 
water;  and  at  45 . 5 0  F.,  11.5  times.  At  a  decreasing  tempera- 
ture, it  becomes  gradually  thicker,  becoming  pale  and  turbid 
with  increasing  cold,  and  congeals  to  a  solid  yellow  mass  at 
16.50  F.  At  266°  F.,  it  commences  to  boil,  and  after  boiling 
for  some  time  at  482°  to  5540  F.,  until  it  has  lost  about  one- 


456 


THE  MANUFACTURE  OF  LEATHER. 


twelfth  of  its  weight,  it  becomes  thicker,  viscous  and  sticky, 
and  furnishes  varnishes.  By  heating  it  still  further,  until  it  has 
lost  one-sixth  of  its  weight,  it  becomes  still  thicker,  the  product 
being  printers'  ink.  By  heating  linseed  oil  to  6o8°  to  7070  F., 
it  ignites  and  burns  quickly  without  further  external  heating, 
until  tar  and  carbon  remain.  By  interrupting  the  burning  by 
covering  the  boiler,  there  remains  a  brown,  turpentine-like  sub- 
stance, the  so-called  bird  lime.  Linseed  oil  is  soluble  in  1.5 
parts  of  ether,  in  forty  parts  of  ninety  per  cent,  spirits  of  wine, 
in  five  parts  of  absolute  alcohol.  It  is  miscible  in  all  propor- 
tions with  chloroform,  oil  of  turpentine,  bisulphide  of  carbon, 
etc.    Its  elementary  composition  is  : 

Cold  Drawn.  Hot  Pressed. 

Carbon   78.11  per  cent.  75-27  per  cent. 

Hydrogen   10.96     "  10.80  " 

Oxygen   10.93     "  '3-85  " 

100.00  per  cent.      100.00  per  cent. 

Linseed  oil  is  a  mixture  of  linolein,  the  glyceride  of  linoleic 
acid,  which  forms  the  principal  constituent,  about  eighty  per 
cent.,  olein,  palmitin  and  myristic  acids.  Nitric  acid,  of  1.30 
specific  gravity,  colors  linseed  oil  sulphur  yellow,  and  if  the 
acid  contains  some  nitrous  acid,  yellow-greenish,  which,  how- 
ever, soon  changes  to  red-brownish.  Fuming  nitric  acid  pro- 
duces on  the  point  of  contact  a  red-brown  zone,  while  the  acid 
itself  is  colored  green.  By  shaking  the  mixture  becomes  dirty 
cherry-brown,  which  later  on  becomes  somewhat  paler.  Sul- 
phuric acid  causes  first  a  green  color,  which,  however,  soon 
changes  to  brown.  By  mixing  ten  drops  of  linseed  oil  with 
three  drops  sulphuric  acid,  a  red-brown  resinous  mass  is  formed. 
A  mixture  of  sulphuric  and  nitric  acids  produces,  first,  a  yellow 
color,  which  changes  to  gray-green,  and,  later  on,  to  a  dirty 
green-brown. 

Five  parts,  by  weight,  of  linseed  oil,  causes  the  temperature 
to  increase  from  590  F.  to  1940  F.,  a  difference  of  1340.  The 
temperature  of  linseed  oil  adulterated  with  colza  oil  rises  only — 


ENAMELED  LEATHER,  ETC. 


457 


With  5  per  cent,  of  colza  oil,  to  i63.5<-'  F. 
"    10     "  "  "     160.00  F. 

"    15     "  "  "     157.0°  F. 

u    20     «  «  «     153.0°  F. 

u    2j     «  «     j^o.o0  F. 

"  30     "         «  "     146.5°  F. 

Solution  of  nitrate  of  silver  causes  a  somewhat  red-brown 
coloring.  Zinc  chloride  produces  no  effect.  Ammonia,  potash 
lye  and  lime  water  produce  yellowish  liniments.  Caustic  alka- 
lies saponify  linseed  oil  very  quickly,  yielding  soaps  of  little 
solidity.  By  saponification,  linseed  oil  gives  ninety-five  per 
cent,  of  fatty  acids  and  five  per  cent,  of  glycerine.  The  above- 
mentioned  formation  of  a  brown  resinous  mass,  by  mixing  ten 
drops  of  linseed  oil  with  three  drops  of  sulphuric  acid,  is  very 
characteristic  as  regards  adulterations.  In  the  presence  of  for- 
eign oils,  such  as  colza,  poppy  seed,  nut,  cotton-seed  oil,  etc., 
the  oil  does  not  form  a  brown,  viscous  resinous  mass.  The 
linseed  oil  alone  is  changed  to  a  resin,  the  brown  resinous  flakes 
floating  in  the  admixed  oils.  An  admixture  of  fish  oils  is 
readily  recognized  by  their  peculiar  odor  and  taste,  or  by  phos- 
phoric acid,  of  the  consistency  of  syrup,  which  colors  linseed 
oil  yellow-brown,  but  fish  oils  red,  which  is,  however,  soon 
changed  to  black-brown.  Even  Scotch  cod-liver  oil,  which  is 
now  brought  into  commerce  almost  inodorous  and  of  a  very 
pale  color,  shows  this  change  with  phosphoric  acid.  An  adul- 
teration with  even  T^  per  cent,  of  fish  oil  can  also  be  de- 
tected by  the  red  color  produced  by  sulphuric  acid.  Concen- 
trated hydrochloric  acid  added  to  linseed  oil  gives  a  yellow 
mixture.  If  hemp  oil  be  present,  the  mixture  is  yellow-green, 
because  hydrochloric  acid  mixed  with  hemp  oil  gives  a  char- 
acteristic grass-green  color.  An  addition  of  resin  (colophony, 
etc.)  is  recognized  by  the  white,  lumpy  precipitate  which  is 
formed  by  shaking  the  linseed  oil  with  spirits  of  wine,  and 
compounding  the  alcoholic  solution  with  alcoholic  solution  of 
sugar  of  lead. 

Linseed  oil  is  extensively  used  in  the  manufacture  of  paints, 
printing  ink,  varnishes,  and  in  the  finishing  of  enameled  and 


458 


THE  MANUFACTURE  OF  LEATHER. 


patent  leather,  leather  dressing,  etc.,  and  for  the  preparation 
of  water-proof  stuffs,  floor  cloths,  elastic  rollers,  etc.  Lin- 
seed oil  boiled  to  the  consistency  of  caoutchouc  served  form- 
erly for  the  manufacture  of  bougies,  catheters  and  elastic 
probes.  To  prepare  such  caoutchouc  mass,  the  linseed  oil  is 
brought  to  a  very  thick  consistency  by  boiling  for  at  least 
twenty-four  hours,  and  is  then  boiled  a  few  hours  longer  with 
diluted  nitric  acid.  The  mass  is  plastic,  and  becomes  hard  on 
contact  with  the  air.  By  dipping  in  hot  water  it  regains  its 
softness,  and  on  cooling  solidifies  again  to  a  caoutchouc-like 
mass. 

Linseed  oil  is  sold  under  four  different  forms,  viz. :  raw,  re- 
fined, boiled  and  artists'  oil.  Of  these,  by  far  the  most  im- 
portant, commercially  speaking,  is  the  boiled.  The  selection 
of  the  oil  to  be  boiled  is  a  matter  of  the  utmost  consequence 
to  the  oil  boiler  and  varnish  maker,  since  the  beauty  and  dura- 
bility of  the  paints  mixed  with  it  depend  largely  upon  its  qual- 
ity. If  the  seed  be  not  fully  ripe  the  oil  expressed  abounds  in 
mucilage,  water  and  pulpy  matter,  while  more  or  less  acid  is 
also  present.  If,  on  the  other  hand,  the  seed  be  full  grown  and 
ripe,  the  oil  is  limpid,  pale  colored  and  of  a  highly  refractory 
power.  To  summarize  the  chemical  changes  induced  in  lin- 
seed oil  by  exposure  to  the  air,  it  may  be  said  that  the  oil 
dries,  or,  in  other  words,  that  it  passes,  by  mere  absorption  of 
oxygen  from  the  atmosphere,  from  a  fluid  to  a  solid  state. 
From  this  known  property  was  derived  the  theory  that  it  was 
necessary  to  heat  with  certain  metallic  acids  from  which  the 
oils  might  derive  oxygen  previous  to  its  exposure  to  the  air, 
thus  shortening  the  time  subsequently  needed  for  complete  ab- 
sorption. Various  oxides  were  made  use  of  for  this  purpose; 
plumbic  oxide  (litharge),  red  lead  and  anhydrous  binoxide  of 
manganese.  More  recently  the  last  two  named  oxides  have 
been  employed  conjointly,  and  to  these  agents  have  been 
added  lead  oxide  or  plumbic  acetate,  zinc  sulphate,  etc.  The 
occasional  addition  of  umber  serves  only  to  deepen  the  color 
of  the  oil. 


ENAMELED  LEATHER,  ETC. 


459 


The  reasons  for  boiling  linseed  oil  are  principally  two:  First, 
that  drying  may  be  facilitated  when  the  oil  is  spread  upon  thin 
surfaces,  either  alone  or  mixed  with  paints.  The  second,  that 
it  may  serve  as  a  vehicle  for  the  mechanical  suspension  of  the 
finely  divided  particles  constituting  a  paint,  thus  enabling  them 
to  adhere  to  the  surface  on  which  they  are  spread. 

It  must  not  run  into  drops,  nor  must  it  leave  the  coloring 
matter  behind  ;  the  color  must  be  carried  by  it,  evenly  diffused 
over  the  whole  surface  over  which  the  paint  is  laid.  The  object 
to  be  obtained  is  to  secure  a  coating  impervious  alike  to  liquids 
and  gases.  It  may  sometimes  happen  that  even  when  the 
process  of  boiling  has  been  performed  properly,  and  with  the 
utmost  care,  the  result  may  prove  unsatisfactory  to  the  con- 
sumer. This  may  somtimes  be  traced  to  circumstances  entirely 
independent  of  the  process  of  manufacture.  The  quality  of  the 
seed,  green  or  ripe,  new  or  old,  the  climate,  and  the  soil  in 
which  the  seed  was  grown — all  of  these  exert  a  marked  in- 
fluence upon  the  product.  The  different  varieties  of  seed  call 
for  separate  and  distinctive  treatment.  All  oil  boilers  should 
test  the  drying  qualities  of  each  batch  of  oil. 

One  tried  and  approved  test  is  to  dip  into  the  oil,  when  cool, 
a  piece  of  well-sized  paper,  which  is  afterwards  hung  up  to  dry. 
Thoroughly  well  boiled  oil  will  produce  a  crystalline  surface 
over  nearly  the  entire  portion  of  the  sheet  dipped  in  the  oil.  If 
the  boiling  has  been  imperfect,  the  upper  portion  of  the  paper's 
surface  will  simply  be  greasy,  and  only  the  lower  portion  will 
show  the  varnished  coating.  When  the  touch  of  a  finger  to  the 
submerged  portion  of  the  paper  shows  no  grease  adhering  to  it, 
the  boiling  may  be  said  to  be  complete.  Reference  has  already 
been  made  to  the  use  of  heat  for  the  purpose  of  driving  off  the 
mucilage  from  the  seed,  The  philosophy  of  the  process  con- 
sists in  the  throwing  off  of  the  water  (probably  held  by  the 
mucilage)  a  yellow  froth  mounting  to  the  surface  of  the  grad- 
ually heating  oil.  The  continued  application  of  the  heat 
evolves  numerous  gases.  Before  the  attainment  of  the  result 
hoped  for  from  the  heat,  however,  a  temperature  of  between 


460 


THE  MANUFACTURE  OF  LEATHER. 


6oo°  and  7000  F.  has  been  obtained.  When  the  partially  de- 
structive distillation  has  effected  the  desired  change  in  the  oil, 
the  liquid  assumes  a  deep,  permanent  (sometimes  reddish) 
brown. 

In  the  opinion  of  some  manufacturers,  the  depth  of  this 
brown  is  the  best  test  by  which  to  gauge  the  thoroughness  of 
the  boiling.  The  old-fashioned  way  of  fire  heating  has  been  to 
a  very  considerable  extent  abandoned,  steam  being  employed 
as  a  substitute. 


CHAPTER  XXX. 


HORSE  LEATHER. 

THE  manufacture  of  horse  hides  for  footwear  originated  in 
Denmark,  and  from  there  it  followed  the  coast  of  the  Iberian 
peninsula,  and  was  largely  developed  in  Hamburg.  There  it 
took  root  immediately  and  was  developed  gradually  to  the 
highest  degree  of  perfection. 

From  Hamburg  the  art  spread  to  Austria,  Poland,  the 
Russo-German  provinces  and  Scandinavia,  which  have  each 
manufactured  some  very  handsome  horse  leather  footwear. 

England  and  France  are  also  manufacturing  this  leather  to 
some  extent;  but  in  the  United  States  there  is  but  little  done 
in  this  line  of  manufacture.  At  the  Philadelphia  Exhibition  in 
1876  all  other  kinds  of  leather  produced  in  this  country  were 
exhibited,  horse  leather  being  the  only  exception. 

The  proper  method  of  liming  and  working  out  these  hides  in 
the  beam-house  is  the  foundation  for  a  good  finished  product. 
The  tanning  of  horse  hides  is  not  generally  understood  in  this 
country,  simply  because  the  work  in  the  beam-house  is  not 
properly  comprehended.  It  is  conceded  by  all  that  in  the 
vicinity  of  Hamburg  and  Bremen  and  in  Holstein,  the  tanners  are 
experts  in  turning  out  horse  butts.  These  are  limed  differ- 
ently from  any  other  raw  material.  The  hides  are  soaked 
three  or  four  days,  according  to  the  time  of  year.  They  are 
fleshed  the  second  day  in  soak.  After  that,  put  them  in  a  very 
foul  lime.  If  it  is  not  foul  enough  to  suit,  add  hen  manure  to  the 
lime,  so  that  the  hides  will  be  very  slippery  on  the  flesh  side. 
This  makes  them  very  flacculent,  so  a  deep  impression  can  be 
made  with  the  finger.  As  soon  as  the  hairs  are  loose,  put  the 
hides  in  a  strong  lime  made  with  fresh  water;  for  every  15 

(461  ) 


462 


THE  MANUFACTURE  OF  LEATHER. 


butts  three  gallons  of  unslaked  lime.  After  slaking,  the  lime 
is  allowed  to  cool  off  thoroughly.  The  hides  are  then 
handled  immediately,  and  for  three  days  twice  a  day.  This 
strong  lime  swells  them  up  greatly,  thereby  loosening  the 
so-called  "  spiegel."  The  unhairing  is  next  done,  and  the 
flesh  shaved  off  the  butts  thoroughly.  They  are  then  bated  in 
hen  manure.  They  are  required  to  be  so  slippery  on  the 
grain  side  that  it  would  be  difficult  to  hold  them,  and  the  dirt 
is  thoroughly  worked  out  of  them.  Stamping  in  warm  water 
is  the  next  process.  The  butts  are  put  in  fresh  water  over 
night  and  in  a  very  light  oak  liquor. 

The  usual  time  which  the  sides  remain  in  the  handling 
liquors  is  six  or  seven  days,  and  they  are  then  laid  away  twice 
in  ground  bark,  both  lay-aways  extending  through  about 
seven  weeks. 

Upon  being  removed  from  the  second  lay-away  the  sides 
are  hung  on  poles  and  exposed  to  the  open  air  to  harden,  and 
are  then  dampened  and  split,  but  the  operation  of  splitting 
horse  hides  by  machinery  is  much  more  difficult  than  that  for 
other  species  of  hides,  and  requires  considerable  experience. 

In  Hamburg,  Germany,  where  a  large  quantity  of  horse 
leather  is  manufactured,  the  splitting  machine  is  not  employed, 
the  custom  being  to  soak,  unhair  and  flesh  the  hides,  and  then 
to  cut  the  butt  at  once  by  taking  off  a  few  thicknesses  with  the 
fleshing  knife. 

The  sides  split  by  the  splitting  machine  are  next  flattened 
by  having  their  shanks  and  bellies  leveled  off  with  a  currier's 
knife. 

From  this  point  the  process  of  tanning  and  currying  horse 
leather  is  the  same  as  has  been  described  for  the  side  of  upper 
leather. 

Horse  leather  is  also  finished  in  imitation  of  kangaroo  and 
other  grains. 

Cordovan. — Horse  hides  for  shoe  purposes  usually  have  the 
butt  or  shell  cut  out  in  the  tanyard ;  they  come  into  the  cur- 
rier's hands  with  the  hind  shank  left  on.    The  first  process  is 


HORSE  LEATHER. 


463 


to  soak  them  down,  after  which  the  mane  is  cut  out,  the  shanks 
removed  and  the  hides  split  down  the  back.  They  are  then 
slicked.  We  find  the  best  way  is  to  slick  them  well  on  the  flesh 
side ;  it  extends  the  hide  more,  and  less  weight  is  taken  off. 
Generally  they  are  shaved  over  when  they  are  in  sides ;  the 
bellies  are  then  cut  off,  so  that  the  only  beam  work  required  is 
to  level  the  thick  parts  for  cordovan.  With  regard  to  the 
soaking,  we  find  that  sumac  liquor  is  preferable  to  water;  it  im- 
proves them,  and  does  not  wash  out  the  tan.  After  shaving, 
the  hide  should  be  scoured  on  both  flesh  and  grain  side,  taking 
care  not  to  "fur"  or  break  the  grain.  There  is  generally  a 
great  deal  of  "  bloom  "  or  dirt,  gathered  from  the  tan,  that 
must  be  carefully  cleaned  from  the  grain.  By  doing  this,  the 
grain  becomes  open  and  the  leather  softer,  allowing  it  to  absorb 
as  much  as  possible  of  the  sumac  liquor,  commonly  called 
"compo"  in  the  trade.  After  scouring  they  are  placed  in  the 
"  compo"  and  well  handled  once  or  twice  a  day.  Every  time 
they  are  handled  they  should  be  laid  up  for  an  hour  or  two 
before  being  again  placed  in  the  "compo."  If  they  are  well 
tanned,  two -or  three  days  is  quite  sufficient  for  them  to  lie  in  it. 
The  liquor  should  be  warmed  every  day.  When  finally  taken 
out  of  the  liquor  they  are  slicked  out,  either  on  the  flesh  or  grain 
side;  the  flesh  is  better,  as  it  leaves  the  "compo"  in  the  grain. 
After  hanging  in  shed,  in  order  to  stiffen  a  little,  they  are  taken 
down  and  set  on  the  grain  side,  which  should  be  well  oiled  and 
as  much  dubbin  put  on  the  flesh  side  as  the  substance  and 
quality  of  the  leather  will  carry. 

They  are  then  re-hung  in  the  shed  until  quite  dry.  They 
should  lie  a  few  days  in  the  grease  before  blacking  (called  in 
the  trade  seasoning).  The  blacking  should  be  done  on  the 
grain  side,  and  if  the  grain  is  in  any  way  damaged  they  should 
be  first  buffed  with  a  turned  slicker  or  knife.  When  the  black 
has  well  gone  into  the  grain,  bottom  size  and  hang  them  up  to 
harden.  Then  dubbin  them  again  and  lay  them  by  for  a  day  or 
two,  taking  care  that  they  do  not  get  dry.  Afterward  set  them 
off  on  the  flesh  and  on  the  grain  with  a  dull  slicker,  and  hang 


464 


THE  MANUFACTURE  OF  LEATHER. 


them  in  a  good  warm  stove  to  dry  off.  The  flesh  side  is  then 
cleaned,  the  grain  is  slicked  with  a  dull  slicker  and  some  dub- 
bin rubbed  in.  After  laying  by  for  a  few  days  the  grease  is 
slicked  off",  the  finishing  size  put  on,  and  the  cordovan  is  ready 
for  sale.  With  regard  to  the  "compoing"  where  a  drum  is  not 
used,  the  best  way  is  to  put  it  in  large  tubs  or  vats  and  well 
handle  the  hides. 

One  of  the  most  notable  and  distinguished  achievements  in 
the  production  of  chrome  leather,  which  deserves  to  be  chron- 
icled, is  in  the  making  of  a  wax  finish  on  chrome-tanned  horse 
hide  butts  (cordovan)  and  on  calf  skins.  This  has  been 
accomplished  by  Hahn  &  Stumpf,  of  Harrison,  N.  J.,  who  use 
the  Dennis  one  bath  system  of  chrome  tanning.  The  firm  also 
make  a  chrome  tanned  horse  hide  front,  with  a  kangaroo  finish, 
which  is  certain  to  find  favor  with  shoe  manufacturers.  The 
chrome  tanned  and  wax  finished  cordovan  goloshes  and  calf- 
skins are,  however,  a  distinct  and  important  advance  in  the  art 
of  leather  making,  and  young  Henry  Stumpf  is  deserving  of 
much  credit  for  his  ingenuity  in  accomplishing  this  result. 
The  writer  has  seen  this  leather,  and  is  well  convinced  that  it  is 
superior  to  the  old  style  of  bark  tanned  wax  leather.  Messrs. 
Hahn  &  Stumpf  will  undoubtedly  secure  a  large  and  increasing 
trade  among  shoe  manufacturers  with  their  new  line  of  chrome 
tanned  leather. 

Many  horse  hides  are  bought  and  sold  in  Hamburg,  Ger- 
many, where  dealers  say  that  if  Americans  made  a  more  thor- 
ough selection  there  would  be  a  great  increase  in  their  pur- 
chases of  horse  hides.  Mule  and  horse  hides  should  be  sepa- 
rated. Mules  are  unknown  in  Germany.  Horse  hides  should 
be  classified  into  primes,  seconds  and  thirds,  and  into  sizes. 

Horse  Hides  for  Enamel. — These  are  generally  split  down 
the  back,  the  shank  removed  and  dressed  in  sides.  They  are 
shaved  very  level,  scoured  on  flesh  and  grain,  put  into  some 
good  sumac  and  well  handled  for  a  day,  then  taken  out  and 
slightly  slicked  oft"  on  the  flesh.  Some  linseed  oil  is  then  put 
on  them  and  they  are  put  in  the  shed,  hanging  them  as  wide 


HORSE  LEATHER. 


465 


apart  as  they  possibly  can  be  to  get  stiffened.  When  fit  to  take 
down  set  them  well  on  the  flesh  and  the  grain,  and  roll  them 
with  a  straight  or  cross-grained  roller ;  hang  them  in  the  shed 
to  dry;  when  dry  take  them  down,  stone  well  on  the  flesh, 
whiten  them  over  the  beam  or  with  a  turned  slicker,  then 
bruise  on  the  flesh  and  slightly  run  the  grain  up.  They  are 
then  ready  to  be  enameled. 

Horse  Hides  for  Plain  Enamel. — Are  dressed  in  the  same 
manner  as  grain  enamel,  with  the  exception  that  they  are  buffed 
all  over  on  the  grain,  and  are  generally  shaved  much  thinner 
than  the  grain ;  they  also  are  not  rolled  or  printed ;  when  dry 
they  should  be  whitened.  After  being  well  stoned  on  the 
buffed  side,  as  well  as  bruised  on  the  flesh,  they  are  ready  to  be 
enameled. 

Horse  Hides  for  Memcl. — Some  are  dressed  in  sides,  others 
without  the  bellies  on,  and  the  butt  pieces  cut  off  and  dressed 
for  cordovan,  but  the  bellies  and  shanks  are  sometimes  put  on 
for  memel.  They  are  shaved,  scoured  and  "  compoed,"  slicked 
out  of  compo  on  the  flesh,  then  hung  up  in  the  shed  to  samm 
or  stiffen.  When  sufficiently  stiff,  they  are  set  and  printed  on 
the  grain,  then  stuffed  on  the  flesh  and  hung  up  to  dry.  When 
dry,  they  are  seasoned  and  bottom  sized  and  a  little  oil  put  on 
the  grain.  When  a  little  stiffened,  they  should  be  grained  up 
so  as  to  make  the  print  of  the  roller  show  up  well.  Then  put 
them  in  the  hot  room  or  shed  to  get  thoroughly  dry.  The  flesh 
must  then  be  cleansed.  Raise  the  grain  again,  oil  them  off  and 
they  are  fit  for  sale,  to  be  cut  up  for  shoes  or  any  other  purpose. 
30 


CHAPTER  XXXI. 


ALLIGATOR  LEATHER. 

A  FASHIONABLE  material  for  small  valises,  satchels,  porte- 
monnaies,  cigar  cases,  etc.,  is  the  skin  of  the  alligator,  and  in 
addition  to  uses  enumerated  it  has  also  been  employed  for 
uppers  of  men's  and  women's  shoes. 

In  all  the  Gulf  States,  from  Florida  to  Texas,  these  saurians 
are  hunted  to  supply  the  demand. 

Alligator  leather  has  been  in  vogue  for  a  long  time,  but  dur- 
ing the  past  fifteen  years  the  slaughter  of  the  alligator  has  been 
prosecuted  with  great  activity. 

R.  W.  Smiley  and  B.  M.  Gopelrivitch,  special  agents  of  the 
Census  Bureau,  completed  a  tour  of  the  bayou  district  of 
Louisiana,  having  traveled  over  1,000  miles  through  the  net- 
work of  bayous,  lakes  and  bays.  Among  the  subjects  investi- 
gated by  them  was  that  of  alligator  hunting,  formerly  an  indus- 
try of  no  little  importance  in  Louisiana,  giving  employment  to 
several  hundred  men  and  furnishing  a  large  amount  of  leather 
quite  popular  in  the  manufacture  of  shoes,  trunks,  bags,  etc. 
This  industry,  which  reached  its  height  about  ten  years  ago,  is 
reported  to  be  nearly  dead,  confined  to  a  very  few  bayous  and 
lakes,  the  saurian  population  of  the  state  having  been  destroyed 
by  the  hunters. 

The  alligators  now  killed  are  much  smaller  than  formerly. 
There  are  stories  of  saurians  of  the  past  forty  feet  in  length, 
but  they  are  probably  apocryphal,  and  from  twelve  to  sixteen 
feet  will  represent  the  largest  of  late  years.  They  have  now 
dwindled  down  to  barely  half  this  size,  and  are  so  scarce  that 
one  can  travel  an  entire  day  through  the  swamps  without  see- 
ing one,  and  a  great  majority  of  the  people  in  Southern  Louis- 

(466) 


ALLIGATOR  LEATHER. 


467 


iana  have  never  encountered  a  wild  one.  There  are  very  few 
breeding  alligators  left,  and  the  saurian  will  probably  be  extinct 
in  the  State  in  the  next  ten  years,  except  a  few  tame  ones  kept 
in  the  parks. 

Notwithstanding  the  reports  to  the  contrary,  the  alligators 
were  rather  innocent  animals.  Occasionally  they  stole  young 
pigs,  and  there  is  a  tradition  that  they  had  a  weakness  for  pick- 
aninnies, but  there  are  not  over  half  a  dozen  cases  recorded  of 
people  being  hurt  by  them,  and  they  seemed  thoroughly  indis- 
posed to  attack  man.  They  succeeded,  however,  in  keeping 
the  streams  of  the  State  nearly  destitute  of  fish,  and  the  fishing 
will  probably  improve  with  their  destruction,  now  so  imminent. 

Brazil  is  now  our  chief  source  of  supply  for  alligator  skins, 
which  are  only  of  fair  quality. 

These  skins  are  usually  packed  for  shipment  in  barrels  and 
are  green  salted.  The  salting  is  often  poorly  done,  and  if  the 
skins  are  allowed  to  remain  too  long  in  the  barrels  they  become 
heated  and  the  grain  sides  thereby  so  injured  that  they  have  to 
be  finished  into  second-class  leather. 

Only  the  skin  from  the  belly  and  sides  is  used ;  the  back 
with  its  heavy  coat  of  scales  is  cut  out  and  thrown  away  as 
worthless. 

All  the  skins  show  great  uniformity,  being  of  a  bluish  black 
hue  on  the  sides  and  a  peculiar  bluish  white  under  the  belly, 
and  each  skin  is  curiously  checkered  in  oblong  divisions,  which 
being  separated  by  intersecting  grooves,  and  wrinkled,  give  the 
peculiar  appearance  seen  in  all  alligator  leather. 

The  trade  in  these  skins  receives  them  of  all  sizes  from  three 
feet  up,  the  average  prices  paid  at  New  Orleans,  La.,  ranging 
from  fifteen  cents  each  for  the  smallest  to  about  one  dollar  for 
the  largest.  The  skins  most  in  demand  are  about  seven  feet 
long.  Those  of  the  monster  alligators  ranging  from  ten  to 
fifteen  feet  long  are  not  much  desired.  Under  the  continual 
destruction  of  alligators  the  supply  is  rapidly  diminishing,  and 
it  is  now  but  a  question  of  a  few  years  when  it  will  be  impos- 
sible to  obtain  these  skins  at  a  price  that  will  justify  their  gen- 
eral employment. 


468 


THE  MANUFACTURE  OF  LEATHER. 


To  supply  the  demand  for  cheap  articles,  imitation  alligator 
leather  is  now  being  largely  produced. 

The  alligator  leather  of  this  country  and  the  kangaroo  leather 
of  Australia  are  similar  in  the  respects  that  they  both  depend 
upon  wild  animals  to  supply  the  material  for  their  manufacture, 
and  the  business  is  therefore  to  some  extent  precarious. 

At  the  place  of  shipment,  the  skins  from  young,  middle- 
aged,  and  old  alligators  are  thrown  promiscuously  into  barrels, 
and  the  first  step  when  they  arrive  at  the  tannery  is  to  assort 
the  small  and  medium-sized  from  the  larger  ones,  which  are 
kept  separate. 

The  skins  are  then  thrown  into  vats  containing  clear,  cold 
water,  and  in  these  soaks  the  smaller  ones  remain  about  two 
days  and  the  large  ones  four  days. 

They  next  go  into  vats  of  lime,  which  should  not  be  so  strong 
as  for  depilating,  and  remain  from  eight  to  fourteen  days,  ac- 
cording to  size. 

Each  day  the  skins  are  reeled  into  stronger  lime,  great  care 
being  observed  not  to  rot  the  tender  portion  during  this  swell- 
ing. 

The  bate  of  hen  manure,  into  which  they  next  pass,  is  made 
quite  weak,  and  in  this  bate  the  skins  are  gently  agitated  by 
means  of  the  usual  England  wheel,  the  period  for  which  they 
remain  being  from  ten  to  fifteen  hours,  according  to  size. 

They  are  next  cleansed  in  a  wash  wheel  and  then  thrown 
into  a  vat  containing  hemlock  liquor  of  about  40  strength,  and 
every  other  day  are  shifted  into  stronger  liquor,  until  at  the 
end  of  about  twenty  days  it  has  been  increased  to  about  200 
strength. 

A  gentle  agitation  of  the  tanning  liquor  during  the  last  twelve 
days  is  very  beneficial,  as  it  aids  in  the  more  thorough  tanning 
of  the  skins,  and  prevents  the  settlement  of  the  sediment  of  the 
liquor  into  the  creases,  which  is  liable  to  rot  the  tender  portions, 
especially  those  of  young  alligators. 

After  being  subjected  to  the  tanning  process  just  described, 
the  skins  are  hung  in  the  open  air  to  harden.    They  are  then 


ALLIGATOR  LEATHER. 


469 


carried  into  the  finishing  room,  and  eight  or  ten  skins  are  piled 
one  upon  the  top  of  another  and  placed  in  a  clamp,  the  flesh 
side  being  uppermost.  The  flesh  sides  are  then  softened  by 
the  operator  with  a  tool,  the  object  being  to  throw  up  the 
rougher  portions,  which  are  then  lightly  cut  off  with  a  currier's 
knife. 

If  the  skins  are  intended  to  be  manufactured  into  upper 
leather  they  are  again  placed  in  the  tanning  liquor  of  8°  or  io° 
strength,  and  in  this  they  remain  for  six  or  eight  days,  during 
which  period  they  are  gently  agitated. 

After  being  removed  from  the  final  tanning  liquor  the  skins 
are  scoured  by  hand  on  a  slate  table,  first  on  the  flesh  and  next 
on  the  grain  side,  the  tools  used  being  the  scouring  brush,  stone 
and  slicker. 

After  being  scoured  they  are  placed  in  the  air  to  harden,  and 
when  not  quite  dry  they  are  carried  into  the  shop  and  stuffed 
by  hand,  tallow,  fish  oil  and  a  small  quantity  of  rosin  being  used. 

They  are  next  "set  out"  and  are  then  carried  to  the  finishing 
room  and  blackened  on  the  grain  side  with  a  preparation  of 
logwood  and  copperas. 

They  are  next  glassed  by  hand,  and  if  a  gloss  is  desired  they 
are  "pasted  over  the  black"  and  hung  up  in  the  finishing  room 
to  dry  over  night. 

In  the  morning  the  skins  are  re-glassed  and  immediately  fin- 
ished by  gumming  them  over  on  the  grain  side  with  a  prepa- 
ration of  gum  tragacanth,  and  are  then  measured  and  ready  for 
market. 

The  skins  not  intended  for  the  manufacture  of  upper  leather 
are  not  blacked,  but  are  finished  in  their  natural  color,  which 
is  a  yellowish-brown,  and  are  used  for  satchels,  pocketbooks,  etc. 


CHAPTER  XXXII. 


RUSSIA  CALF. 

To  make  colored  or  Russia  calf,  get  as  good  a  selection  of 
green  skins  as  possible,  and  free  from  salt  rust.  Soak  in  packs 
of  convenient  size,  and  so  that  the  skins  in  each  pack  are  not 
too  widely  different  in  weight.  The  number  of  skins  in  a  pack 
should  be  controlled  by  the  size  of  the  soaks,  limes,  and  tan 
vats.  The  following  quantities  of  green  skins  will  make  con- 
venient soaks  in  paddle  vats  of  700  gallons,  with  good  inflow 
of  water,  during  time  of  soaking.  We  would  say  400  five-pound 
skins,  300  six-pounds,  250  eight-pounds,  200  ten-pounds,  and 
150  twelve  to  fifteen  pounds. 

Trim  and  soak  ten  to  sixteen  hours,  according  to  season  of 
year  and  necessity  of  hurry.  About  ten  hours'  soaking  in  the 
summer  is  usually  sufficient  for  ordinary  stock.  Dry  skins 
should  be  milled  five  hours  or  more  after  soaking  so  as  to 
soften  properly  and  be  in  good  condition  for  the  limes.  It  is 
very  important  that  skins  be  fairly  well  broken  in  the  hide  mill, 
or  they  will  cause  trouble.  Make  up  limes  60  parts  of  lime 
and  35  parts  of  sulphide  of  sodium.  Both  materials  to  be  dis- 
solved in  a  barrel  of  warm  water  before  putting  in  the  vat. 
Swab  each  skin  before  putting  in  the  vat,  by  dipping  flesh  in  a 
box  of  large  size  containing  solution  of  sulphide  and  lime  in 
same  proportion  as  in  vat.  As  each  skin  is  transferred  from 
swabbing  box  to  vat  they  should  be  immersed  by  being  shoved 
down  with  a  pole.  Haul  on  the  following  day  and  strengthen 
with  same  proportion  of  sulphide  of  lime.  Put  back  and  haul 
again  on  the  fifth  day,  and  strengthen,  and  the  skins  will  be 
ready  for  unhairing  on  the  eighth  or  tenth  day. 

From  the  limes  or  beam  house  the  skins  should  go  into  a 

(470) 


RUSSIA  CALF. 


4;  I 


rapidly  revolving  wheel  pit,  with  constant  inflow  of  water. 
Wash  thoroughly  three  or  four  hours  until  water  is  clear  and 
the  skins  free  of  lime.  Then  flesh  on  the  machine  and  fine- 
hair  the  grain  if  possible.  Leave  in  clear  cold  water  over  night 
or  at  least  for  five  hours  before  bating.  The  lime  and  sulphide 
dissolve  the  hair  completely  and  give  a  soft  skin.  The  new 
bate  can  be  made  by  using  three  bushels  of  hen-manure,  or 
two  bushels  for  renewing  the  old  bate  or  pure.  The  liquors 
should  be  900  F.  Before  putting  back  into  bate,  use  wheel 
pit  for  this  work  and  keep  stock  constantly  in  motion  during 
this  operation.  After  puring,  rinse  well  and  work  on  flesh  side, 
then  put  skins  into  luke-warm  water  in  tub  before  working 
well  on  grain.  Then  wash  thoroughly  in  cold  water  and  let  the 
skins  drain  before  putting  them  in  tan  vat.  By  this  method 
of  depleting,  packs  can  be  thoroughly  reduced  in  three  hours 
and  then  worked  so  that  they  can  be  put  in  tan  the  same  day. 

In  tanning  use  wheel  pits  of  convenient  and  uniform  size, 
each  containing  about  700  gallons  of  liquor.  Divide  tan-room 
into  three  divisions.  First — Sufficient  vats  for  handling  and 
coloring.  Second — Vats  for  continuing  tanning  from  the  strik- 
ing liquors  to  the  time  of  skiving.  Third — Vats  for  tanning 
out  stock  after  skiving. 

Liquors  should  be  four  to  five  degrees  barkometer.  Into  the 
water  pits  should  be  put  six  or  seven  pails  of  gambier  liquor 
standing  75  degrees  in  the  pails;  also  four  or  five  pails  of  sedi- 
ment gambier  after  the  boiling.  When  the  liquor  is  ready,  im- 
merse the  stock  and  run  the  paddle  wheel  30  to  40  minutes  to 
assure  a  good,  uniform  color  on  grain.  Strengthen  twice  daily 
with  two  or  three  pails  gambier  and  sediment,  morning  and 
evening,  and  run  wheel  three  times  daily,  ten  to  fifteen  minutes 
each  time.  Continue  in  this  manner  four  or  five  days.  Then 
haul  packs  and  strike  out  flesh  on  machine.  Now  transfer  to  the 
second  and  stronger  liquors  of  eight  or  ten  degrees.  Hold  packs 
in  this'liquor  for  14  days,  moving  them  around  in  the  vats  by  run- 
ning the  wheel  three  times  daily  from  eight  to  ten  minutes  each 
time,  and  strengthen  with  two  or  three  pails  of  gambier,  meas- 


472 


THE  MANUFACTURE  OF  LEATHER. 


uring  75  degrees,  in  the  pails.  This  should  be  done  once  daily 
for  14  days,  when  stock  will  be  about  struck  through.  With- 
draw and  set  out  on  flesh  by  machine.  Then  skive  and  put 
back  in  third  section  of  finishing  liquors  of  12  to  15  degrees  for 
seven  days.  Strengthen  each  day  with  two  pails  of  gambien 
and  run  wheel  each  time  10  to  15  minutes.  This  wheeling  or 
turning  over  of  the  packs  hastens  the  tanning  and  changes  the 
position  of  each  skin  in  the  vat,  thus  assuring  a  uniform  color 
on  grain.  By  using  one  pail  of  salt  per  vat  each  week  the 
liquor  will  be  kept  sweet  and  the  tanning  done  more  rapidly- 
Striking  or  coloring  liquors  should  be  run  down  the  sewer  after 
each  pack  is  removed,  as  such  liquor  is  dirty  and  worthless 
after  a  week's  use. 

After  the  stock  is  tanned  out,  it  may  be  strengthened  and 
cleared  by  running  in  drum  with  seven  pounds  alum  and  five 
pounds  salt  to  every  125  skins.  Use  seven  pails  of  water  for 
dissolving  this  material.  After  running  for  thirty  minutes* 
horse  the  leather  for  five  hours,  so  as  to  drain  well.  Then  oil 
in  drum,  using  five  quarts  neatsfoot  oil  to  every  125  skins. 
Keep  drum  turning  thirty  minutes  in  oil.  Then  stop,  withdraw 
the  pack  and  use  machine  for  setting  out  flesh.  Then  hang  in 
loft  to  dry. 

As  the  majority  of  Russia  tanned  skins  need  cleansing  be- 
fore shaving  to  the  desired  substance  required  by  the  tanner,  it 
is  necessary  to  remove  the  excess  of  tan  or  other  surplus  matter 
by  washing  in  a  mill,  using  twenty  pails  of  water  to  each  125 
skins.  The  water  should  be  700  F.,  and  the  stock  run  in  it  15 
or  20  minutes — no  longer.  From  the  drum,  set  out  on  flesh 
side  on  machine.  Then  oil  on  grain  by  hand  with  neatsfoot 
oil,  and  dry  out  in  moderately  warm  room. 

After  the  stock  is  dried,  wet  down  and  horse  up ;  drain  five 
hours  before  shaving.  After  shaving,  fat-liquor  as  follows  :  To 
each  60  skins  use  two  gallons  of  fat  liquor  and  one  pint  of  birch 
oil  well  beaten  into  the  fat  liquor.  Run  the  stock  30  minutes, 
and  then  set  out  on  flesh  by  machine  and  grain  by  hand.  Use 
glass  on  grain ;  then  put  on  hooks  to  dry  slowly.    When  dry 


RUSSIA  CALF. 


473 


take  down  to  color,  using  100  pounds  of  dry  leather  to  each 
batch  colored.  Give  each  of  the  ioo-pound  batches  seven  pails 
water,  900  F.,  in  drum  to  wet  up  stock  before  coloring.  Run 
stock  25  minutes.  Drain  off  any  excess  of  water  not  taken  up 
by  the  leather.  Throw  stock  well  up  on  each  side  of  the  door 
of  drum,  so  that  no  skin  will  lie  in  dye  before  starting  the  drum 
in  coloring.  Boil  up  dyes  with  one  pail  water,  and  add  six 
pails  water  of  8o°  F.  to  stock  in  mill ;  then  add  dyes  and  start 
mill  immediately.  Run  stock  twenty  minutes  in  dyes  and  to 
each  change  of  dyes. 

After  coloring  and  before  removing  from  mill,  drain  off  any 
excess  of  dye  and  apply  egg,  using  one  pint  of  egg-yolk  to 
each  dozen  skins.  Run  stock  in  egg  for  fifteen  minutes;  then 
horse  up  from  mill  and  put  on  hooks  to  dry.  When  dry,  lay 
in  sawdust  to  dampen  for  staking.  Stake  well  on  machine; 
then  trim,  and,  if  stock  requires  it,  use  three  gallons  of  fat 
liquor  in  six  pails  of  warm  water.  In  wetting  down  stock  to  set 
out,  the  latter  should  be  done  carefully  on  flesh  and  grain. 
Then  dry  out  and  brush  on  grain  with  powder  brushes.  Season 
and  pack  down  four  or  five  hours  before  rolling.  Roll  hard 
and  air  off  in  warm  room.  Stake  light  on  grain  and  roll  light. 
Then  measure  the  stock,  which  will  then  be  ready  for  shipping 
away. 

ANOTHER  PROCESS  FOR  COLORING. 

After  shaving  skins  to  uniform  substance  for  the  work  in 
hand,  fat-liquor  and  set  out  on  flesh  by  machine,  and  grain  by 
hand.  Dry  cut;  then  take  100  pounds  dry  leather  in  one 
batch  for  coloring.  Put  stock  in  drum  with  twenty-five  gallons 
water  of  900  F.  Run  stock  fifteen  minutes  in  water,  then 
drain  off  any  excess  of  water  not  taken  up  by  stock  in  drum. 
Bail  up  dyes  in  one  pail  water.  Give  stock  in  drum  six  pails 
water  of  8o°  F.,  and  add  dyes.  Use  the  same  amount  of 
water  to  each  change  of  dyes  and  run  stock  twenty  minutes  in 
each  change  of  dyes. 

After  coloring,  rinse  in  clear  water  and  egg,  giving  a  propor- 
tion of  two  egg  yolks  to  each  skin  colored. 


474 


THE  MANUFACTURE  OF  LEATHER. 


Color  No.  2  is  composed  of  the  following  dyes : 


ist  Dye. 
8  ozs.  Acid  Brown  N. 
4  ozs.  Orange  D. 


86  ozs.  Nankin. 

%  oz.  Methyline  O. 

i>%  ozs.  Bismarck  Brown  R. 


2d  Dye. 


Color  No.  3:   ist  dye — 15  ozs.  acid  yellow,  F. ;  2d  dye — 
1}^  ozs.  Bismarck  Brown  R:  15  ozs.  aniline  yellow. 
Color  No.  4  is  made  up  as  follows : 


After  coloring,  dry  out  in  room  of  8o°  to  900  F.  When 
dry  put  in  sawdust  and  dampen  to  stake.  Stake  well,  then  wet 
down  to  set  out.  Set  flesh  on  machine  and  grain  by  hand. 
Dry  out  in  moderately  warm  room.  When  dry,  brush  with 
power  brush  on  grain,  then  season,  using  seven  quarts  vinette 
and  whites  of  two  eggs  in  two  and  one-half  gallons  water.  Use 
flannel  pad  to  apply  seasoning.  After  seasoning,  pack  down 
grain  to  grain.  Let  lie  four  hours.  Then  roll  hard,  air  off  in 
warm  room.  Stake  lightly  on  grain.  Roll  lightly  and  stock 
is  ready  for  shipping  room.  For  the  above  description  we  are 
indebted  to  Hide  &  Leather,  of  Chicago. 


ist  Dye. 


2d  Dye. 


40  ozs.  Bronze  No.  2. 
13  ozs.  Acid  Brown  N. 
18  ozs.  Orange  D. 


84  ozs.  Nankin. 

32  ozs.  Bismarck  Brown  R. 

22  ozs.  Leather  Brown  No.  2. 


CHAPTER  XXXIII. 


THE   MANUFACTURE  OF  RUSSIA  LEATHER — RUSSIAN  METHOD 
OF  PREPARING  AND  APPLYING  THE  MORDANT  AND 
DYE — MANUFACTURE  OF  BIRCH  OIL. 

THE  MANUFACTURE  OF  RUSSIA  LEATHER. 

In  Russia  a  variety  of  leather  is  made  called  Jnften,  or  in- 
correctly Juchten  (Russia  leather).  It  is  a  well-tanned  leather 
of  unusual  strength,  great  flexibility  and  almost  impervious  to 
water.  Moreover,  it  is  not  attacked  by  insects,  because  it  pos- 
sesses a  penetrating  odor  very  disagreeable  to  them,  but  so 
acceptable  to  many  men  that  they  perfume  their  linen  with 
pieces  of  the  leather,  or  carry  pocket  books,  cigar  cases,  or  the 
like,  made  from  it. 

Russia  leather  attracts  a  great  deal  of  attention  on  account 
of  its  peculiar  odor,  and  in  other  countries  frequent  attempts 
have  been  made  to  impart  a  similar  odor  to  other  kinds  of 
leather. 

Russia  leather  is  employed  more  for  articles  of  luxury  than 
of  utility,  and  does  not  moulder  under  the  influence  of  damp- 
ness. 

But  its  use  for  book-binding  in  the  numerous  public  libraries 
of  this  country  is  being  rapidly  superseded  by  red-colored 
Morocco  leather,  which  is  attractive,  more  durable,  and  less 
costly. 

Russia  leather  is  also  much  used  in  the  manufacture  of 
jewelry  cases,  handkerchief  cases,  and  other  toilet  articles,  also 
for  albums,  traveling  bags,  etc. 

It  derives  its  name  from  the  country  whence  it  originated, 
and  where  it  is  more  especially  manufactured. 

It  is  a  fact  now  established  that  tanners  of  other  countries 

(  475  ) 


476 


THE  MANUFACTURE  OF  LEATHER. 


are  well  able  to  produce  an  article  very  similar  and  very  much 
cheaper  than  real  Russia  leather,  but,  however,  minus  its  fine 
odor.  In  a  paper  published  on  the  manufacture  of  leather  in 
Russia,  written  by  two  officials  in  the  Russian  War  Office,  the 
peculiar  odor  imparted  to  the  leather  was  attributed  to  the  tar 
extracted  from  the  birch  tree.  After  the  Exhibition  at  Phila- 
delphia, a  company  of  American  leather  manufacturers  purchased 
200,000  puds  of  the  oil  (1  pud  =  36  pounds),  but  the  results 
obtained  with  it  were  anything  but  satisfactory.  The  price  of 
this  birch-tar  oil  varies  from  3  to  4  roubles  per  pud ;  the  oil, 
however,  is  so  much  adulterated  that  Russian  leather  manu- 
facturers, as  a  rule,  are  provided  with  means  of  their  own  for 
its  preparation,  and  in  Germany  an  essence  is  made  by  Dr.  C. 
Heintzel,  of  Luneburg,  which  gives  to  leather  an  odor  very 
nearly  approaching  to  that  of  Russia  leather. 

The  Russia  leather  manufactories  are  situated  mostly  in  the 
districts  of  Viatka,  Orel,  Iver,  and  Kasan,  where  are  numerous 
birch  forests.  Here  the  hides  of  young  cows  are  especially 
used  for  the  manufacture  of  Russia  leather — white,  red,  and 
black.  The  raw  or  wet  hides,  in  order  to  deprive  them  of  hair 
and  flesh,  are  laid  in  lime  or  ashes  mixed  with  lime,  and  they 
are  kept  there  until  the  hair  begins  to  loosen.  After  the  un- 
hairing,  the  hides  are  placed  in  the  vats  for  swelling,  then 
washed  in  running  water,  cut,  salted,  placed  in  a  receptacle 
containing  a  mixture  of  flour  and  warm  water  and  shaken  and 
turned  about  vigorously.  By  this  means  a  fermentation  is  set 
up,  and  the  acid  thereby  produced  takes  away  the  last  remains 
of  the  lime.  This  is  the  oldest  mode  of  operation  and  the  one 
most  in  vogue,  but  in  some  tanneries  the  process  varies. 

The  tanning  should  begin  with  the  placing  of  the  hides  in 
the  pits,  and  with  their  treatment  in  weak  liquor,  and  there  are 
four  shifts  which  last  over  20  or  25  days.  About  46  pounds  of 
bark  are  used  on  an  average  for  each  hide.  After  being  rinsed 
and  sorted,  the  hides,  being  still  damp,  though  not  wet,  are 
spread,  grain-side  downwards,  upon  a  table,  and  smeared  with 
a  mixture  of  birch-tar  and  melted  fat.    Every  hide  intended 


RUSSIA  LEATHER. 


477 


for  white  or  red  leather  receives  in  this  way  one-half  pound 
of  tar  and  one  pound  of  fat.  The  mixture  is  put  on  carefully 
with  the  hand  so  as  to  be  perfectly  smooth  and  equal.  When 
this  is  done  the  hides  are  hung  out  in  an  open  shed  to  dry. 
Those  intended  for  red  leather  are  smeared  in  drying  with  a 
solution  of  alum,  and  the  grain  side  of  each  hide  treated  with 
sandalwood  dye  put  on  cold.  Those  intended  for  black  leather 
are  rubbed  on  the  grain  side  first  with  a  solution  of  alum,  and 
next  with  a  solution  of  logwood  put  on  almost  boiling  hot,  and 
then,  to  set  the  color,  brushed  over  with  a  solution  of  green 
vitriol  (sulphate  of  iron).  In  some  cases,  instead  of  the  vitriol 
a  liquor  is  used  which  is  obtained  by  putting  old  rusty  iron 
into  an  acid  decoction  gone  into  a  fermentation  and  called  by 
the  workmen  "  quass."  The  hides  are  then  once  more  rubbed 
over  on  the  flesh  side  with  birch-tar  and  melted  fat  in  the 
proportion  of  one-half  pound  to  each  hide.  If,  however,  the 
production  of  the  so-called  birch-tar  leather  is  aimed  at,  one 
and  a  half  pounds  of  each  substance  is  taken. 

As  a  final  preparation  the  leather  is  softened  in  water  and 
thoroughly  worked  upon  the  tree,  smoothed  and  kneaded,  and 
afterwards  rubbed  briskly  with  the  graining  tool,  and  lastly  with 
a  tool  of  glass,  stone,  or  steel  on  the  grain  side,  alternately 
rolled,  and  greased  a  little  on  the  grain  side.  The  black  leather 
is  also  smeared  on  the  grain  side  with  a  mixture  of  birch-tar 
and  fat. 

In  other  processes  of  tanning,  the  hides  after  being  unhaired 
and  fleshed  are  piled  up  with  alternate  layers  of  ground  willow 
bark  in  great  vats,  and  then  covered  with  a  solution  of  willow 
bark.  They  are  moved  from  ten  to  six  times  in  the  tan  pit,  and 
the  spent  bark  is  each  time  replaced  with  fresh,  until  the  tan- 
ning is  completed.  In  Russia  the  hides  of  cows  or  young 
bullocks  are  employed  by  preference,  and  horse  hides  are  also 
used,  especially  in  the  interior  of  Russia.  In  France,  however, 
these  hides  are  hardly  employed  at  all,  but  only  the  skins  of 
rams,  goats  and  calves.  This  is  done  because  the  French 
Russia  leather  is  principally  used  in  book-binding  or  for  cover- 


478 


THE  MANUFACTURE  OF  LEATHER. 


ing  cases  and  similar  work,  for  which  that  made  in  Russia  is 
entirely  unsuitable,  in  the  first  place  because  it  is  much  too 
coarse,  secondly,  because  it  is  so  permeated  with  fat  as  to 
render  it  undesirable  for  the  purposes  mentioned. 

In  the  preliminary  preparation  for  tanning,  it  is  essential  that 
the  hides  be  entirely  freed  from  lime.  The  Russians  employ  a 
peculiar  process  for  this  purpose,  which  is,  however,  as  the  re- 
sult shows,  very  effective.  They  swell  the  hides  for  several 
days  in  an  acid  bath  composed  of  rye  and  oatmeal  and  water, 
to  which  a  sufficient  quantity  of  leaven  is  added  to  set  up  fer- 
mentation in  the  whole  mass. 

After  this  operation  has  been  completed,  the  hides  are  tanned 
first  in  oak  tan,  then  in  willow,  and  finally  to  remove  their  stiff- 
ness are  softened  in  a  flour  pap.  This  is  composed  of  about  a 
pound  of  rye  flour  for  each  hide,  and  ten  pounds  of  salt  to 
each  four  hundred  hides.  After  they  have  laid  in  this  mixture 
several  days,  they  are  washed  off,  dried  lightly,  and  then 
greased  with  a  mixture  of  two  parts  of  train  oil  and  one  of  birch 
oil.  Of  this  mixture  about  half  a  pound  is  used  for  each  cow 
or  horse  hide.  It  is  well  rubbed  in  upon  the  flesh  side  with 
the  flat  hand,  and  left  for  some  days  to  take  full  effect,  which  is 
generally  secured  by  hanging  the  hides  under  an  airy  shed. 
This  completes  the  process  as  it  is  generally  carried  on  with 
them. 

Russia  leather  is  also  manufactured  in  Austria,  where  it  is 
tanned  with  tan-bark.  Austrian  tanners  do  not  understand  the 
art  of  bringing  out  the  natural  grain,  so  they  give  their  Russia 
leather  an  artificial  grain,  produced  by  lines  which  intersect 
each  other  at  acute  angles,  thus  forming  rhomboidal  lozenges. 
The  false  Russia  leather  may  be  at  once  recognized  by  this 
regular  artificial  grain,  which  the  Russians  never  produce. 

In  order  to  obtain  the  birch  oil  the  Russians  proceed  just  as 
the  Polish  peasants  do  in  the  preparation  of  their  pine-tar.  If 
they  are  especially  careful,  they  do  not  dig  a  pit  in  the  ground^ 
in  which  to  place  the  wood  to  be  distilled,  but  employ  two 
large  pots.    The  two  pots  are  filled  with  the  cork-bark  of  the 


RUSSIA  LEATHER. 


479 


birch,  each  one  having  a  little  opening  in  the  bottom,  by  which 
ventilation  is  possible.  The  sides  of  the  pots,  which  are  placed 
one  above  the  other,  are  smeared  with  clay.  The  bark  in  the 
under  pot  is  ignited  through  the  opening,  this  is  placed  upon 
another  empty  pot,  and  the  whole  is  left  to  itself.  In  the  bot- 
tom pot  there  collects  considerable  tar,  quite  a  quantity  of  im- 
pure wood-acid  (pyroligneous  acid),  and  upon  this  floats  the 
clear  birch  oil.  This  process  may  be  called  the  rational  one, 
but  the  customary  way  is  to  dig  a  pit  in  the  ground,  cover  the 
sides  with  clay,  and  dig  a  ditch  at  the  bottom  of  the  pit,  in 
which  is  placed  a  cask  or  barrel  to  receive  the  tar  and  other 
products  of  distillation.  The  pit  is  then  filled  with  birch  bark, 
which  is  piled  up  in  the  shape  of  a  mound.  This  is  covered 
with  sod,  in  which  at  various  places  air  holes  are  made,  to 
permit  the  exit  of  the  smoke  and  the  entrance  of  air.  Al- 
though both  processes  are  very  crude  and  yield  only  poor  re- 
sults, they  suffice  for  the  needs  of  the  uncleared  Russian  forests, 
where  raw  material  costs  nothing.  In  America,  if  birch  tar  or 
oil  is  desired,  it  is  secured  by  dry  distillation,  by  heat  applied 
from  the  outside,  whereby  everything  that  is  in  the  wood  is 
saved,  and  all  that  is  left  in  the  vessel  in  which  the  distilling 
is  done  is  good  charcoal. 

The  birch  oil,  which  is  lighter  than  water,  transparent  and 
moderately  volatile,  is  mixed  with  train  oil  in  varying  pro- 
portions, from  one  part  train  to  two  of  birch  oil  or  the  exact 
reverse.  This  latter  oil  is  called  in  Russian  daggeat.  If  the 
green  buds  and  young  twigs  of  the  birch  be  distilled  by  them- 
selves, they  give  an  agreeable  oil  smelling  something  like  rose 
oil.  This  the  French  claim  to  use  for  the  preparation  of  the 
finer  sorts  of  Russia  leather.  Since,  however,  these  do  not 
smell  in  the  least  like  rose  oil,  either  the  claim  concerning  the 
oil,  or  the  statement  that  it  is  used  in  their  preparation,  or  both, 
are  untrue.  In  fact,  there  are  many  different  claims  made  con- 
cerning the  manufacture  of  Russia  leather;  this  is  partly  due 
to  the  actual  employment  of  varying  processes,  partly  to  the 
fact  that  the  travelers  from  whom  the  information  comes,  not 


48o 


THE  MANUFACTURE  OF  LEATHER. 


being  skilled  in  the  craft,  either  understand  what  is  told  them 
incorrectly,  or  actually  receive  false  information.  This  last 
happens  especially  with  uncultivated  people,  who  having  only  a 
meagre  industry,  are  especially  jealous  of  it,  and  do  not  will- 
ingly give  information  concerning  it  to  strangers. 

The  red  color  of  Russia  leather  is  caused  by  a  surface  dye- 
ing with  sandal-wood  or  Guinea  red-wood  or  Sanders  wood. 
After  the  hides  are  tanned  they  are  soaked  in  alum  water, 
placed  together  two  by  two  in  a  sack,  and  covered  with  the 
dyeing  liquid.  If  the  leather  is  desired  to  become  black, 
sulphate  of  iron  is  added  to  the  wood  decoction.  The  greasing 
is  always  the  conclusion  of  the  process,  and  after  the  hides  are 
placed  on  poles,  about  which  they  are  wound  many  times,  and 
stretched  and  pulled  to  give  them  the  necessary  flexibility. 

The  method  of  manufacturing  this  leather  we  shall  now  de- 
scribe as  it  is  conducted  in  the  United  States,  for  the  reason 
that  the  machines  here  employed  are  so  much  superior  to  those 
used  in  Russia  that  an  article  almost  equal  to  the  native  Russia 
leather  is  produced,  and  in  a  much  shorter  time. 

The  hides  used  in  the  production  of  this  leather  are  generally 
cow  or  steer  hides  and  large  calf-skins,  seldom  goat  or  sheep- 
skins. 

In  tanning,  the  first  operations,  such  as  soaking,  unhairing, 
fleshing,  etc.,  are  conducted  in  the  same  manner  as  for  other 
kinds  of  leather. 

The  swelling  of  the  hide  is  one  of  the  essential  points  for  its 
successful  manufacture,  and  is  proceeded  with  in  the  following 
manner :  For  one  hundred  cow  or  steer  hides  take  twenty-two 
pounds  of  rye  flour  and  ten  pounds  of  oat  flour,  and  knead  with 
yeast  and  a  little  salt. 

Allow  this  dough  to  ferment,  and  then  thin  with  sufficient 
water  to  immerse  the  one  hundred  hides,  which  are  left  in  this 
preparation  for  forty-eight  hours,  and  when  they  are  sufficiently 
swollen,  the  hides  are  placed  in  a  tepid  solution  of  willow  and 
poplar  barks.  The  hides  are  handled  in  this  solution,  twice  a 
day,  for  at  least  eight  days.    They  are  next  immersed  in  a 


RUSSIA  LEATHER. 


liquor,  the  tanning  ingredients  of  which  are  composed  equally 
of  oak,  pine,  and  willow  barks,  and  in  this  liquor  they  must  also 
be  handled  at  least  twice  a  day.  After  eight  days  the  last- 
named  liquor  is  renewed  and  the  hides  are  hardened  and  split, 
and  then  again  placed  in  the  liquor  for  another  eight  days,  care 
being  observed  to  handle  as  before.  After  this  time  the  hides 
are  sufficiently  tanned. 

The  period  of  tanning  can  be  considerably  shortened  by 
using  a  revolving-wheel,  placed  over  the  tan-vat  to  gently  agi- 
tate the  liquor,  such  as  the  England  wheel. 

After  being  tanned  the  hides  are  cut  into  sides,  and  scoured 
and  then  rinsed  in  clear  water  and  allowed  to  drip  and  dry. 
The  sides  are  then  slightly  dampened  and  allowed  to  temper 
for  two  days  and  then  greased  with  a  mixture  of  birch  oil  and 
seal  oil,  two-thirds  of  the  first  and  one-third  of  the  second,  ac- 
cording to  the  thickness  of  the  leather. 

For  heavy  leather  a  coat  of  this  grease  is  applied  to  the  grain 
side.  The  leather  is  then  thoroughly  greased  on  the  flesh  side, 
and  afterwards  fulled.  The  leather  is  next  set  out,  then 
whitened,  and  finally  boarded,  and  when  well  dried  it  is  pre- 
pared for  dyeing. 

Before  dyeing,  the  sides  are  submitted  to  an  albuminous 
solution,  which  acts  as  a  mordant  to  make  the  color  penetrate 
more  easily. 

The  leather  is  dyed  black  or  red,  but  the  latter  color  is  most 
used. 

The  dye  is  made  of  a  decoction  of  sandal  or  Sanders  wood, 
the  quantity  of  which  must  be  judged  by  the  operator,  who 
obtains  the  correct  shade  by  repeated  essays  on  small  fragments 
of  leather. 

Sandal  or  Sanders  wood  and  cochineal  give  a  richer  color, 
and  are  sometimes  used. 

The  leather  must  be  dyed  in  several  coats,  taking  care  that 
the  preceding  one  is  well  dried  before  applying  another  coat, 
the  dye  being  applied  with  a  brush  to  the  grain  side. 

After  dyeing,  the  leather  is  again  impregnated  with  a  mixture 
3i 


482 


THE  MANUFACTURE  OF  LEATHER. 


of  birch  oil  and  seal  oil,  which  must  be  made  to  penetrate  as 
much  as  possible,  by  rubbing  energetically  with  a  flannel  rag 
on  the  grain  side. 

As  a  mordant  in  Russia  they  use  chloride  of  tin  prepared  in 
the  following  manner:  Take  5^  ounces  of  nitric  acid,  heat  it 
very  slowly  under  a  chimney  having  a  good  draft  so  as  not  to 
be  affected  by  the  emanations  of  the  acid,  pour  in  this  hot 
solution,  stirring  it  meanwhile  with  a  glass  or  a  wooden  stick, 
1  pound  and  2  ounces  of  salt  of  tin.  This  operation  must  be 
done  in  the  open  air  or  under  the  influence  of  a  strong  draft,  so 
as  not  to  inhale  the  deleterious  vapors  of  the  nitric  acid,  which 
are  excessively  dangerous. 

Stirring  must  be  continued  with  caution  so  as  to  allow  the 
unwholesome  vapors  to  escape ;  when  the  mixture  begins  to 
whiten  add  4^  ounces  of  fuming  hydrochloric  acid,  stirring 
carefully  for  a  few  moments. 

The  liquor  must  be  cooled  and  put  in  hermetically  closed 
bottles,  to  be  kept  in  a  cool  place,  and  before  using  this  liquor 
it  must  be  diluted  in  a  volume  of  from  1  5  to  20  times  its  own 
weight  of  pure  water. 

The  leather  being  prepared  and  cleansed  from  all  foreign 
substances,  the  mordant  is  applied  very  briskly  and  uniformly 
with  a  brush. 

As  coloring  matter  in  Russia  they  use  1  lb.  2  ozs.  of  sandal 
or  Sanders  wood  boiled  for  an  hour  in  1  ^  gallons  of  pure  water. 
This  liquor  is  filtered  and  1  ounce  of  prepared  tartar  and  soda 
dissolved  in  it. 

This  mixture  is  boiled  for  an  hour,  and  it  is  left  standing  for 
a  few  days  before  using,  as  it  is  then  stronger. 

The  sides  destined  for  black  dyeing  are  only  oiled  on  the 
flesh  side,  which  must  be  dried  with  a  woolen  rag,  leaving  the 
grain  half  moist,  and  irreproachably  neat. 

The  leather  is  submitted  two  or  three  times  to  the  mordant, 
according  to  its  thickness,  and  then  dyed  as  many  times  with 
the  warm  dye,  the  temperature  of  which  must  be  raised  if  nec- 
essary; i.  e.,  the  dye  must  only  be  applied  while  warm,  and  if 


RUSSIA  LEATHER. 


483 


the  operation  takes  too  much  time  according  to  the  number  of 
skins,  the  dye  must  be  kept  at  the  proper  temperature. 

The  application  of  the  mordant  and  dye  is  done  with  a  brush 
by  rapidly  spreading  the  liquid  which  is  poured  on  the  leather. 

Rapidity  in  this  operation  is  necessary  in  order  to  spread  the 
dye  equally  on  the  whole  surface  of  the  leather  and  to  insure 
the  same  shade  on  all  its  parts. 

The  first  coat  of  color  is  applied  immediately  after  the  mor- 
dant and  while  the  leather  still  retains  some  of  its  moisture  ;  the 
dye  in  this  manner  taking  more  easily  and  there  being  less  risk 
of  shading. 

It  is  desirable  for  the  good  execution  of  this  work  to  have 
two  men  operating  together;  the  first  applying  the  mordant, 
and  the  second  the  color  immediately  afterward.  Should  the 
color  not  be  uniform  another  coat  is  applied  at  once  with  a 
lighter  solution. 

This  red  color  lasts  as  long  as  the  leather  itself  and  does  not 
damage  it,  whatever  may  be  the  time  of  its  stay  in  the  ware- 
house. 

After  the  application  of  the  dye  the  leather  must  be  slightly 
moistened  on  the  flesh  side  with  some  tan  juice  and  dried,  and 
then  grained. 

The  red  Russia  leather  acquires  a  brilliant  appearance  when 
its  colored  side  has  been  coated  with  gum  tragacanth  solution 
by  means  of  a  sponge  ;  this  gelatinous  water  must  neither  be 
too  thick  nor  be  applied  in  too  large  a  quantity. 

For  graining  the  hides  the  same  methods  are  followed  as  for 
the  manufacture  of  Morocco  leather;  but  instead  of  being 
"  straight  grained "  or  "  pebbled "  the  finish  is  a  diamond- 
shaped  grain. 

A  graining  machine,  especially  for  Russia  leather,  was  in- 
vented by  Towein,  who,  unfortunately,  died  when  he  was  finish- 
ing it. 

However,  his  work  survives  him,  and  his  graining  machine 
is  in  use  in  large  French  establishments  and  its  success  is  com- 
plete. 


484 


THE  MANUFACTURE  OF  LEATHER. 


Black  colored  Russia  leather  is  prepared  in  the  same  manner 
as  has  been  described,  but  is  stained  by  the  application  of  ace- 
tate of  iron,  aniline  and  other  blacks  being  also  used. 

MANUFACTURE  OF  .  BIRCH  OIL. 

This  oil  is  commonly  called  Russia  oil,  but,  notwithstanding 
this  name,  the  bark  of  the  birch  tree  of  all  countries  will  pro- 
duce it,  and  it  is  in  the  whitish,  membranous  epidermis  of  the 
bark  that  the  oil  exists,  and  this  should  be  carefully  separated 
from  the  ligneous  or  woody  matter. 

The  bark  is  considered  preferable  when  it  has  been  freshly 
gathered. 

If  the  distillation  of  the  oil  is  done  in  the  spring,  some  birch 
buds  are  mixed  with  the  bark ;  a  more  limpid  oil  is  thus  ob- 
tained and  its  odor  is  more  penetrating  and  delicate,  resemb- 
ling a  little  the  flavor  of  the  rose.  This  mixture  also  facili- 
tates the  separation  of  the  oil,  which  when  thus  prepared  is  of 
a  lighter  color,  from  the  very  small  quantity  of  soot  it  contains. 

Many  systems  are  followed  to  distill  the  birch  oil ;  some  of 
them,  very  simple,  are  within  the  capabilities  of  any  one;  the 
others,  more  elaborate,  require  the  science  and  complicated 
stills  of  the  chemist.  This  oil  can  be  readily  obtained  by  dis- 
tilling the  bark  in  iron  cylinders  placed  horizontally  in  a  furnace. 

In  each  of  the  methods  of  distillation,  to  be  hereafter  de- 
scribed, separate  the  birch  oil  from  the  tar,  acid,  etc.,  under- 
lying it,  and  keep  it  in  a  glass-stoppered  bottle  or  some  other 
close  vessel. 

The  following  is  a  simple  method  for  distilling  this  oil : 
Above  any  kind  of  receiver  place  an  earthen  pot  of  a  conveni- 
ent capacity  with  a  hole  pierced  through  its  bottom ;  fill  the 
pot  with  the  bark,  put  fire  to  the  bark,  and  cover  the  earthen 
vessel  with  another  of  similar  capacity,  also  having  a  hole  in 
its  bottom.  The  bark  burns  slowly,  the  smoke  and  the  hetero- 
geneous products  of  this  kind  of  distillation  evaporate  through 
the  aperture  in  the  upper  vessel,  and  the  oil  runs  through  the 
lower  opening  into  the  receiver  below. 


RUSSIA  LEATHER. 


485 


Another  method,  which  is  that  of  Fischerstroem,  is  a  little 
different  from  this,  although  based  on  the  same  principles.  To 
carry  it  out,  fill  an  iron  caldron  with  bark  and  cover  with  a 
convex  lid,  in  the  middle  of  which  a  hole  is  made,  for  the  intro- 
duction of  an  iron  tube;  above  this  caldron  another  one  is 
placed  and  the  two  secured  together,  the  second  caldron  hav- 
ing a  hole  in  the  bottom,  through  which  passes  the  iron  tube  of 
the  first  caldron,  but  which  must  not  touch  its  bottom. 

The  two  caldrons,  suitably  united,  must  be  hermetically 
closed  by  means  of  clay.  They  are  then  inverted  and  half 
buried  in  the  ground,  the  one  containing  the  bark  being  upper- 
most, and  it  is  daubed  over  with  a 
mixture  of  sand  and  clay.  A  large 
wood  fire  is  built  around  this  iron 
caldron,  so  as  to  bring  it  to  a  white 
heat.  When  everything  is  cooled 
the  distillation  is  complete  and  the 
caldrons  may  be  opened. 

In  the  upper  caldron  there  will 
be  a  fine  coal  powder,  and  in  the 
other  the  products  of  the  distilla- 
tion, i.  e.,  the  birch  oil  floating, 
underlaid  with  a  little  tar,  upon  a 
slight  layer  of  pyroligneous  acid. 

By  Grouvelle  and  Duval-Duval's 
process,  the  material  is  introduced 
into  a  copper  still,  similar  to  those 
used  to  distill  wood  in  the  manu- 
facture of  acetic  acid.  The  receiver  is  so  adapted  as  to  be  im- 
mersed in  water  in  which  the  gaseous  products  are  condensed, 
and,  as  in  the  manufacture  of  acetic  acid,  the  resulting  pro- 
ducts are  pyroligneous  acid,  tar  in  larger  quantity,  and  the  oil 
more  colored,  and  less  abundant. 

The  oil  may  be  obtained  nearly  colorless  by  rectification,  but 
this  is  not  necessary,  unless  the  oil  is  intended  to  be  employed 
on  delicately  colored  leather. 


Fig.  125. 


486 


THE  MANUFACTURE  OF  LEATHER. 


By  repeating  the  distillation  per  descensum,  Payen  ascertained 
that  with  a  simple  apparatus  it  is  possible  to  obtain  an  oil  less 
colored  and  in  the  proportion  of  one-fifth  more,  at  a  tempera- 
ture less  elevated. 

To  construct  this  apparatus,  which  is  shown  in  Fig.  125,  a 
hole  is  made  in  the  bottom  of  an  earthen  furnace  A,  large 
enough  to  receive  the  neck  of  a  matrass  M.  The  furnace  is 
supported  by  two  bricks  placed  upon  the  plank,  which  is  also 
perforated  so  as  to  admit  of  the  passage  of  the  neck  of  the 
matrass,  and  which  rests  upon  the  trestles  C,  C.  The  matrass 
is  filled  to  its  utmost  capacity  with  the  epidermis  of  birch  bark ; 
it  is  inverted  and  passed  through  the  furnace  and  the  board. 
Then  the  neck  is  luted  and  placed  in  the  position  seen  in  the 
figure,  being  supported  by  sand  thrown  into  the  bottom  of  the 
furnace  as  high  as  F,  F,  and  in  order  to  expose  the  matrass  to  a 
uniform  heat,  it  is  protected  by  inverting  over  it  an  earthen 
hemispherical  vessel  or  crucible.  Around  this,  burning  coals 
are  placed,  and  the  fire  is  kept  up  through  two  lateral  openings, 
D,  D,  the  dome  /,  K,  L  being  placed  upon  the  furnace  top. 
Condensed  water  first  trickles  from  the  mouth  of  the  matrass 
into  a  vessel  placed  beneath,  and  this  is  succeeded  by  drops, 
and  then  by  a  constant  stream  of  an  amber-colored  oil.  After 
a  time  this  ceases,  and  it  is  necessary  to  apply  heat  lower  down 
to  the  neck  of  the  matrass,  so  as  to  cause  the  discharge  of  the 
last  portions  of  all  tarry  matters  which  have  condensed  in  it. 

The  products  obtained  by  the  distillation  of  one  hundred 
parts  are  as  follows  : 

A  brown,  oily  matter,  light  fluid  empyreumatic,  soluble  in  ether.  70.00 

Thick  dark-brown  tar,  containing  a  little  oil   5.00 

Water  acidulated  with  pyroligneous  acid   10.00 

Light  spongy  charcoal   12.50 

Gases   2.50 

100.00 

BIRCH  OIL  AND  LEATHER. 

Birch  oil  is  obtained  by  dry  distillation,  and  the  process  by 
which  the  Russian  peasants  effect  the  operation  is  the  most 


RUSSIA  LEATHER. 


487 


simple  that  can  be  imagined.  A  caldron  capable  of  being 
hermetically  closed,  set  in  a  brick  fire-place  above  the  ground, 
is  connected,  by  means  of  a  pipe,  with  another  caldron  buried  in 
the  ground.  That  is  the  whole  of  the  apparatus.  The  upper  ap- 
paratus is  filled  with  dry  birch  bark,  closed  up,  and  then  heated. 
The  vapor  which  the  enclosed  bark  gives  off  finds  its  way  to  the 
buried  caldron,  is  there  condensed,  and  becomes  a  dark-brown 
liquid.  This  is  birch-tar.  The  tar  is  allowed  to  get  quite  cool, 
and  during  this  process  there  rises  to  the  surface  a  vegetable 
acid  contained  in  the  tar,  which  must  be  skimmed  off.  On  the 
tar  being  distilled,  an  oil  with  a  peculiar  smell,  something  like 
that  of  cedar -wood,  is  formed,  and  it  is  this  which  imparts  to 
Russia  leather  its  peculiar  odor. 

Birch-tar,  however,  obtained  in  the  way  described,  contains, 
besides  the  oil  just  alluded  to,  other  oils,  which  possess  a  rather 
unpleasant  empyreumatic  smell.  The  raw  birch  oil  of  com- 
merce, therefore,  gives  out  this  smell  of  burning  to  a  very  much 
greater  extent  than  it  does  the  pleasant  smell,  and  persons  not 
aware  of  this  fact  will  not  recognize  birch  oil  as  Russia  oil,  and 
will  not  risk  applying  it  to  their  leather.  These  oils  possessing 
this  empyreumatic  smell,  however,  are  very  volatile,  and  when  the 
birch-tar  is  spread  upon  the  leather  they  soon  evaporate,  merely 
from  coming  in  contact  with  the  air.  When  this  is  effected,  only 
the  pleasant-smelling  oil  remains,  and  the  well-known  grateful 
odor  of  the  Russia  leather  is  secured.  It  may  be  asked,  "Why 
cannot  the  oils  with  the  burning  smell  be  removed  without  wait- 
ing for  them  to  evaporate  after  being  spread  upon  the  leather?" 
It  is  possible  to  effect  this  by  a  special  treatment,  but  as  the 
process  is  a  very  costly  one,  and  as  only  a  relatively  small  quan- 
tity of  the  pure  oil  is  obtainable  from  the  birch-tar,  the  price 
of  the  pure  oil  would  be  very  high.  Birch  oil  is  a  thick  and 
almost  black  fluid,  and  is  consequently  only  suitable  for  the 
smearing  of  black  leather.  The  oil  distilled  from  it — birch-tar 
oil — is  a  thin  liquid,  and  although  not  much  lighter  in  color 
than  the  oil,  it  is  transparent. 


488 


THE  MANUFACTURE  OF  LEATHER. 


RUSSIA  ODOR  TO  CALF  LEATHER. 

To  impart  the  Russian  odor  to  calf  leather,  the  skins  should 
be  tanned  in  the  ordinary  way  with  oak  bark,  and  then  well 
washed  and  all  the  water  got  out  of  them,  after  which  the  grain 
surface  should  be  lightly  brushed  over  with  a  mixture  made  as 
follows:  60  per  cent,  of  bright  fish  oil,  and  40  per  cent,  of  the 
thin  liquid  birch-tar  oil.  Let  the  skins  then  dry,  and  the  de- 
sired object  is  attained. 

BIRCH-TAR  AND  PINE-TAR  THEIR  DIFFERENTIATION. 

It  is  frequently  very  essential  to  know  for  a  certainty  the 
sources  of  tar.  The  subject  has  been  investigated  by  Hirschsohn, 
who  recommends  the  following  process  for  the  differentiation 
of  birch-tar  and  fir-tar.  At  68°  F.  birch-tar  has  a  specific 
gravity  of  O.925  to  O.945  ;  while  pine  (fir)  tar,  at  the  same  tem- 
perature, is  1.02  to  1.05  ;  the  one  floating  in  water,  while  the 
other  will  sink  if  entirely  freed  of  air.  Birch-tar  agitated  with 
10  volumes  of  water,  abandons  none  of  its  coloring  matter, 
though  the  water,  while  remaining  perfectly  colorless,  acquires 
a  markedly  acid  reaction.  The  addition  of  perchloride  of  iron 
to  the  water,  produces  a  green  color  reaction.  If  2  drops  of 
anilin  and  4  drops  of  hydrochloric  acid  be  added  to  5  ccm.  of 
the  water,  a  yellow  color  reaction  results.  If  I  volume  of  birch- 
tar  be  agitated  with  20  volumes  of  petroleum-ether  and  filtered, 
a  clear,  brownish-yellow  liquid  is  obtained,  which  does  not  be- 
come green  when  agitated  with  a  diluted  solution  of  copper 
acetate. 

The  aqueous  extract  of  fir-tar  is,  on  the  contrary,  colored  a 
marked  yellow,  is  of  acid  reaction,  but  becomes  red  on  the 
addition  of  FeCl2  (instead  of  green).  Treated  with  anilin  and 
HC1,  the  color  passes  to  red.  The  petroleum  solution,  agitated 
with  copper,  becomes  green.  Finally,  when  pine  (fir)  tar  and 
alcohol  are  agitated  together,  the  former  takes  up  no  color. 
If  there  is  any  muddiness,  or  even  cloudiness,  you  may  be 
certain  that  the  tar  is  contaminated  with  birch-tar,  kerosene 
products,  coal-tar,  etc. 


CHAPTER  XXXIV. 


WEIGHTING  OF  LEATHER. 

No  advances  worthy  of  note  have  of  late  been  made  in  the 
art  of  weighting  leather.  The  same  old  methods  are  still  in 
vogue,  and  apparently  give  full  satisfaction.  Weighting  with 
sugar  is  by  far  the  most  common. 

In  testing  leather  which  has  been  weighted  with  sugar,  it  is 
usual  for  the  analyst  to  specify  only  the  percentage  of  sugar  or 
glucose  found,  and  this  particular  percentage  is  then  considered 
as  indicating  the  artificially  added  weight.  Recent  analyses 
have,  however,  proved  that  this  is  no  criterion. 

The  presence  of  sugar  or  other  soluble  matter  is  first  of  all 
indicated  by  the  heavy  shrinkage  which  occurs  in  washing  out 
a  sample  of  leather  thus  weighted.  If  the  loss  is  insignificant 
or  normal  it  may  be  taken  for  granted  that  the  leather  has  not 
been  tampered  with.  Artificial  weighting  is  a  tedious  process, 
and  the  manufacturer  employing  such  methods  at  all  is  sure  to 
do  his  work  thoroughly. 

A  sample  of  sole  leather  was  recently  analyzed  which  showed 
a  washing-out  shrinkage  of  no  less  than  16.8  per  cent.  So  heavy 
a  loss  naturally  presupposed  the  presence  of  artificial  weighting 
matter  in  considerable  proportions.  Further  analysis  showed 
that  only  5.73  per  cent,  of  the  matter  thus  lost  was  sugar,  and 
that  10.3  per  cent,  of  the  total  loss  consisted  of  other  matter, 
which  is  in  itself  a  very  high  percentage  for  sole  leather.  The 
residue  on  being  subjected  to  other  tests  to  determine  the 
presence  of  tanning  matter,  etc.,  developed  so  large  a  percent- 
age of  foreign  non-tanning  substance  as  to  utterly  preclude  the 
possibility  of  the  latter  owing  its  origin  in  entirety  to  the  tan- 
ning materials  employed.    The  nature  of   the  non-tanning 

(489) 


49Q 


THE  MANUFACTURE  OF  LEATHER. 


matter  present  could  not  be  accurately  determined,  but  it 
seemed  to  be  of  vegetable  origin.  The  excessive  presence  of 
non-tanning  matter  may  be  attributed  to  the  fact  that  in  this 
instance,  as  in  all  probability  is  most  often  the  case,  the  tanner 
had  used  molasses  for  weighting  with,  instead  of  a  solution 
specially  prepared  by  himself,  the  former  being  far  cheaper,  as 
well  as  handier.  Molasses  consists  of  about  50  per  cent,  sugar, 
30  per  cent,  non-saccharine  matter  (organic  and  inorganic),  and 
20  per  cent,  water.  According  to  this  estimate,  the  presence 
of  5.7  per  cent,  of  sugar,  as  in  the  instance  referred  to  above, 
would  represent  a  weighting  with  about  9.2  per  cent,  molasses 
(free  from  water). 

This  would  leave  of  the  16.8  per  cent,  total  shrinkage,  a  fur- 
ther loss  of  7.6  per  cent.,  or  a  figure  just  within  the  legitimate 
bounds  of  washing-out  loss  for  sole  leather. 

We  may  thus  conclude  that,  given  the  percentage  of  sugar 
in  analyzing  a  weighted  leather,  if  the  washing-out  loss  still  re- 
mains very  high  after  deducting  the  former,  the  actual  weight- 
ing can  be  fairly  estimated  at  one  and  one-half  times  the 
weight  of  the  sugar  found. 


CHAPTER  XXXV. 


TANNING  AND  DYEING  FURS  AND  HAIR-SKINS. 

THE  hair  is  thicker  in  the  autumn,  and  by  beginning  work  at 
that  time  of  the  year  the  skins  will  be  ready  for  market  when 
the  demand  is  at  its  best. 

TANNING  CALFSKINS. 

In  tanning  calfskins  in  the  hair,  the  tannin  acts  from  the  flesh 
side  only  and  the  hair  will  consequently  be  apt  to  slip  until  the 
tan  reaches  the  hair  follicles.  All  unnecessary  handling  should 
therefore  be  avoided,  and  the  actual  tanning  be  done  as  rapidly 
as  possible,  so  as  to  give  the  hair  no  chance  to  fall  out. 

The  skin  must  of  course  undergo  a  preliminary  thorough 
cleansing,  etc.,  and  as  the  usual  method  of  soaking,  liming,  etc., 
cannot  be  employed,  the  tanner  must  resort  to  special  proces- 
ses. Without  some  kind  of  preparation,  the  tanning  would  be 
a  very  slow  operation  and  the  skin  be  very  apt  to  come  out 
hard  and  tinny. 

Only  perfectly  sound  and  fresh  skins  can,  needless  to  say,  be 
used.  To  remove  all  impurities  the  skins  are  first  soaked  in 
fresh,  clear  water  as  cold  as  the  work  admits  of,  and  the  water 
frequently  changed.  It  is  best  to  use  covered  vats — of  stone- 
ware or  cement  for  preference,  as  these  best  retain  the  required 
low  temperature.  Soaking  in  running  water  is  not  to  be  re- 
commended, as  the  action  is  less  even  and  the  skins  are  apt  to 
accumulate  slime  and  other  impurities  which  make  the  hair 
slip. 

After  soaking  one  day,  the  skins  are  thoroughly  worked  on 
flesh  side,  to  remove  blood,  superfluous  flesh,  etc.  As  this 
operation  has  to  replace  shaving,  etc.,  it  must  be  attended  to 
very  thoroughly,  and  specially  heavy  parts,  as,  for  instance,  the 

(491  ) 


492 


THE  MANUFACTURE  OF  LEATHER. 


pate,  are  either  cut  out  or  rolled  to  same  thickness  as  rest  of 
skin,  which  is  an  operation  requiring  some  experience. 

Next,  place  in  fresh  water,  turning  often ;  finally  work  and 
rinse  again. 

The  skins  are  now  ready  for  plumping.  For  this  purpose 
they  are  soaked  in  a  weak  solution  of  sulphuric  acid  until  suffi- 
ciently swelled  (a  cut  will  then  show  transparent  instead  of 
white).  Then  rinse  again  in  fresh  water  and  place  in  soda  bath 
(5  to  6  pounds  to  enough  water  for  10  skins).  This  is  done 
to  reduce  the  swelling  and  to  neutralize  acidity.  The  soda  is 
then  removed  by  repeated  rinsing  and  by  finally  being  passed 
through  water  to  which  a  little  muriatic  acid  has  been  added. 

Rinse  for  last  time  and  place  in  water  containing  wheat  flour 
2^  pounds  per  105  quarts  of  clean  water.  This  removes  last 
trace  of  acidity  and  makes  the  skins  soft  and  pliable.  They 
are  now  ready  for  tanning. 

As  before  stated,  the  tanning  should  be  done  as  rapidly  as 
possible.  The  strength  of  the  tanning  liquor  is  therefore  grad- 
ually but  not  too  slowly  increased  by  adding  extracts.  As 
soon  as  the  tan  has  taken  hold  thoroughly,  a  fairly  strong  liquor 
may  be  used,  especially  as  in  the  case  of  skins  tanned  in  the 
hair,  a  soft  grain  surface  is  of  slight  importance. 

A  mixture  of  hemlock  and  quebracho  extracts  may  be  re- 
commended. Both  make  a  soft  tannage  and  supplement  each 
other.  The  skins  must  be  thoroughly  tanned,  or  the  grain  is 
apt  to  be  hard  and  peel  off. 

When  thoroughly  tanned,  and  not  before,  the  skins  are  well 
fleshed  to  remove  last  particles  of  flesh,  etc.,  which  might  inter- 
fere with  the  stuffing.  The  latter  can,  of  course,  only  be  done 
from  the  flesh  side. 

First,  rinse  well ;  wash  the  hair  side  thoroughly  in  warm 
soapsuds  and  dry  in  open  air.  The  stuffing  is  applied  warm 
and  at  frequent  intervals.  When  the  grease  is  completely  ab- 
sorbed, grain,  stuff  lightly  again  and  dry  out. 

The  skins  are  lastly  slicked  off,  beaten  and  brushed  out.  The 
finish  may  be  improved  upon  by  waxing  on  flesh  side. 


TANNING  AND  DYEING  FURS  AND  HAIR-SKINS.  493 


FOR  TANNING  FURS,  PELTRIES  AND  DEER  SKINS. 

(1)  All  skins,  whether  for  furs,  other  peltries,  or  leather, 
must  be  thoroughly  freed  from  flesh,  fat  and  foreign  materials. 
To  do  this  beam  with  a  knife,  or  scraper,  and  then  scour  well 
in  suds  of  fine  soap  and  sal  soda,  before  any  tan  stuff  or  color- 
ing matter  is  applied.  Care  should  be  exercised  to  see  that 
the  pelt  is  perfectly  free  from  suds,  by  rinsing  and  wringing ; 
also,  by  beaming  previous  to  tanning. 

(2)  When  the  pelt  is  well  cleaned  and  scoured,  as  above  di- 
rected, make  brine  of  common  salt  at  blood  heat  until  no  more 
will  dissolve.  Then  prepare  a  like  quantity  of  mucilage,  by 
passing  very  warm  water  through  a  fine  sack  filled  with  clean 
wheat  bran.  Also,  dissolve  a  small  quantity  of  good  starch  in 
warm  water.  Let  the  brine,  mucilage  and  starch-water  settle 
till  quite  clear,  then  pour  them  carefully  together  into  a  wooden 
or  earthen  vessel  of  sufficient  dimensions  to  give  free  motion  to 
the  pelts  when  stirred.  Place  the  vessel  where  it  will  keep 
warm  for  two  hours. 

(3)  Dip  the  pelts  in  clean,  strong  alum  water,  at  blood  heat, 
for  two  hours ;  rinse  the  pelts  free  from  the  alum  water,  and 
wring  or  beam  them  as  dry  as  possible. 

(4)  When  all  is  ready,  pour  into  a  mixture  of  brine  and  mu- 
cilage (still  keep  warm).  Add  a  quantity  of  sulphuric  acid 
(oil  of  vitriol),  two  pounds  of  acid  to  ten  gallons  of  water  or 
mixture,  and  put  the  pelts  in  quickly,  stirring  them  as  briskly  as 
possible  for  a  few  minutes.  Take  out  the  pelts,  and  scrape 
flesh  as  clean  and  dry  as  possible,  putting  back  in  same  process 
for  one  hour.  Be  careful  to  have  the  mixture  touch  every  part 
of  each  pelt. 

(5)  Let  the  pelts  hang  in  a  shady,  airy  place,  until  just  dry 
enough  to  turn  white  when  pulled  or  stretched  in  any  direction. 
Continue  the  pulling  and  working  of  each  pelt,  changing  the 
pelt  round  as  it  is  pulled,  to  keep  the  fiber  subject  to  an  even 
effect.  Much  depends  upon  working  the  pelts  at  the  right 
time;  that  is,  when  just  dry  enough  to  turn  white  when  pulled, 
and  by  continuing  the  process  of  working  until  fully  dry. 


494 


THE  MANUFACTURE  OF  LEATHER. 


(6)  When  the  pelts  are  quite  dry  they  should  be  beamed 
over  a  beam,  with  a  dull  beaming  knife,  and  finished  by  polish- 
ing the  flesh  side  with  coarse  sandpaper. 

IN  THE  PROCESS  OF  COLD  TAN. 

( 1 )  Care  should  be  taken  to  clean  the  pelts  free  from  all  for- 
eign substances,  after  which  place  them  in  strong  liquor  made 
of  alum  and  salt.  This  is  to  set  the  fur.  Take  out  and  beam 
well,  then  place  in  tan  liquor  made  as  above.  Stir  often.  Thick 
skins,  such  as  cow  hides  for  robes,  should  remain  from  two  to 
four  days,  according  to  thickness. 

(2)  All  pelts  should  be  cut  down  even  with  the  currying 
knife  before  placing  in  tan.  Furs,  large  and  small,  should  be 
milled  in  sawdust.  They  are  best  handled  in  a  fur  worker  run 
by  power;  this  takes  out  all  remaining  oil  left  in  the  fur. 

DYEING  FUR  SKINS. 

Most  tanners  are  no  doubt  at  some  time  or  other  called  upon 
to  tan  the  skins  of  fur-bearing  animals  of  the  most  diverse 
character,  says  the  SchnJi  und  Leder  of  Berlin.  The  actual 
tanning  process  is  well-known  to  all,  and  the  conscientious  tan- 
ner fulfills  this  part  of  his  commission  to  the  best  of  his  ability, 
although  the  result  often  leaves  much  to  be  desired.  The  main 
object,  from  his  point  of  view,  is  to  see  that  the  hair  is  properly 
set,  and  this  is  usually  accomplished  by  the  use  of  alum ;  the 
appearance  of  the  fur  is  often  looked  upon  as  a  matter  of 
secondary  importance.  By  allowing  the  hair  to  retain  its 
natural  color,  as  is  generally  done,  the  commercial  value  of 
many  varieties  of  peltry  is  less  than  it  might  be  made  if  suitably 
dyed ;  in  fact,  in  some  instances,  where  skins  from  the  same 
species  of  animal  possess  fur  of  totally  different  color,  as  they 
sometimes  do,  it  is  essential,  in  order  to  secure  an  even  appear- 
ance, that  the  pelts  should  be  dyed  uniformly,  thus  enhancing 
their  beauty  and  market  value  considerably,  without  in  any 
manner  detracting  from  the  quality. 

The  dyeing  of  fur  skins  is  a  distinct  branch  of  the  furriers' 


TANNING  AND  DYEING  FURS  AND  HAIR-SKINS.  495 


trade,  and  as  the  skin  itself  will  not  stand  a  heat  of  more  than 
1040  F.,  the  dyeing  process  is  a  very  delicate  operation, 
the  trade  secrets  of  which  are  more  jealously  guarded  than 
those  of  almost  any  other.  Where  the  whole  skin  is  to  be 
dyed,  the  dipping  process  is  resorted  to,  while,  where  it  is  de 
sired  to  color  only  the  lighter  portions,  or  to  darken  the  tips  of 
the  hair,  brushes  are  used  to  apply  the  mordant  and  coloring 
matter,  the  stiffness  of  the  bristles  used  depending  on  the  depth 
to  which  it  is  desired  that  the  color  shall  penetrate.  Suitable 
brushes  are  also  used  to  produce  stripes  or  other  peculiar 
markings,  and  as  coloring  materials :  burnt  gallnuts,  sulphate 
of  iron,  verdigris,  sulphate  of  copper,  etc.  By  means  of  these, 
all  the  shades  of  gray  can  be  produced,  as  also  a  scale  of  tints, 
ranging  from  the  lightest  brown  to  the  most  intense  shade  of 
black. 

Of  late  the  manufacture  of  tar-colors,  v/hich  has  revolution- 
ized the  dyeing  trade  generally,  has,  in  connection  with  the 
newly  introduced  so-called  ursol-colors,  opened  up  a  new  field 
for  the  fur  dyeing  industry,  especially  as  no  particular  skill  as 
a  dyer  is  required  in  using  ursol  colors;  any  tanner  can,  by 
giving  the  matter  some  attention,  arrive  at  very  satisfactory  re- 
sults. 

As  inquiries  are  often  received  from  tanners  as  to  the  dyeing 
of  fur  skins,  we  take  pleasure  in  placing  before  our  readers 
herewith  some  of  the  latest  developments  in  this  field  of  in- 
dustry, taken  from  the  detailed  results  of  a  series  of  experi- 
ments with  ursol  colors  made  by  two  well-known  German  ex- 
perts, the  accuracy  of  whose  observations  have  been  personally 
verified  by  us.  The  account  in  question  appeared  in  issues 
Nos.  1 3  and  1 7  of  the  Faerber  Zcitung. 

Ursol  colors  are  manufactured  by  the  Aktien-Gesellschaft  fiir 
Anilin-Fabrikation  in  Berlin  under  the  trade  marks :  Ursol  D, 
Ursol  P,  Ursol  C  and  Ursol  DB.  Of  these  D  produces  a  dark 
brown  and  black,  P  a  reddish-brown,  C  a  yellowish-brown,  and 
DB  is  specially  adapted  for  bringing  out  a  bluish  or  intense 
black.  A  large  variety  of  shades  can  also  be  obtained  by 
judicious  blending  of  the  various  grades. 


496 


THE  MANUFACTURE  OF  LEATHER. 


Before  a  skin  can  be  colored  it  must  first  be  tanned  and  pre- 
pared, and  all  grease  removed  from  the  hair  so  as  to  make  it 
susceptible  to  the  dye.  The  latter  process  is  technically  desig- 
nated as  "killing  the  skin,"  and  if  properly  performed,  does 
not  rob  the  fur  of  its  elasticity  or  injure  the  skin.  Cold  liquors 
must  only  be  used  in  degreasing. 

Among  the  methods  employed  for  "killing  the  skin,"  the 
lime  process  is  the  one  giving  the  most  satisfactory  results.  It 
consists  of  treating  with  a  degreasing  liquid  prepared  in  the 
following  manner  :  Dissolve  in  two  litres  hot  water  60  grammes 
powdered  sal-ammoniac  and  15  grammes  aluminium  sulphate, 
and  add  to  this,  stirring  briskly,  a  milk  of  lime  made  by  dis- 
solving 200  grammes  unslaked  lime  in  four  litres  of  water. 

The  resulting  solution,  which  should  be  kept  in  well-covered 
stone  jars,  and  should  be  stirred  well  before  using,  is  applied 
with  a  brush  on  the  fur  side  one  or  more  times,  according  to 
how  thorough  a  cleaning  is  necessary,  and  the  skin  is  then 
placed  to  dry  in  the  shade,  in  a  not  too  warm  place;  if  dried 
too  rapidly,  the  hair  loses  its  elasticity  and  the  skin  becomes 
hard. 

When  dry,  the  lime  dust  is  removed  by  beating  and  brush- 
ing, and  the  skin  is  then  ready  for  the  (ursol)  dye  bath, 
although,  if  first  treated  with  a  mordant  of  bichromate  of  potas- 
sium and  cream  of  tartar,  a  saving  of  dye  will  be  effected,  as 
well  as  the  process  of  oxidation  facilitated.  Sulphate  of  iron 
or  sulphate  of  copper  may  also  be  used  as  mordants  when  the 
skins  are  to  be  dyed  black. 

By  replenishing  with  fresh  potassium  bichromate  and  cream 
of  tartar  in  quantities  equal  to  one-third  of  the  original  propor- 
tions, the  bichromate  bath  may  be  used  again  ;  but  after  the 
same  bath  has  served  twice,  or  at  the  most  three  times,  it  is  ad- 
visable to  replace  it  by  an  entirely  fresh  solution. 

After  mordanting,  the  skins  are  rinsed  and  placed  in  the  dye 
liquor,  and,  to  insure  a  uniform  color,  care  should  previously 
have  been  taken  to  work  them  evenly  and  thoroughly  in  the 
bichromate  solution,  stress  being  laid  on  the  point  that  they 
must  always  be  handled  fur-side  down. 


TANNING  AND  DYEING  FURS  AND  HAIR-SKINS.  497 


The  method  of  dyeing  will  be  best  understood  by  a  detailed 
description  of  a  few  representative  examples. 

For  instance,  rabbitskins  may  be  dyed  a  brilliant  golden 
brown  in  the  following  manner:  The  skins  are  cleansed  thor- 
oughly in  a  bath  made  up  of  about  10  grammes  soap  and  10 
grammes  ammonia  to  10  litres  of  water,  in  which  they  are  al- 
lowed to  remain  from  1  to  2  hours,  during  which  time  they  are 
handled  repeatedly;  then  taken  out  and  rinsed  thoroughly. 
They  are  next  soaked  for  about  12  hours  in  a  mordanting 
liquid  of  20  grammes  potassium  bichromate  and  10  grammes 
cream  of  tartar  to  every  10  litres  of  water;  then  removed  and 
rinsed,  and  placed  in  the  dye  liquor,  which  consists  of  6 
grammes  Ursol  P  to  every  10  litres  of  water.  After  10  hours' 
immersion,  the  fur  will  have  taken  on  the  desired  color. 

Goatskins  (Angora)  are  dyed  a  medium  yellowish-brown 
as  follows — Mordant :  20  grammes  potassium  bichromate  and 
10  grammes  cream  of  tartar  per  10  litres  water  (time  of  im- 
mersion 12  hours).  Rinse  well  and  dye  out  with  10  grammes 
of  Ursol  P  and  1  pint  peroxide  of  hydrogen  to  10  litres  of 
water.    Six  hours  is  required  for  this  process. 

Ursol  D,  used  alone,  produces  grey;  with  a  bichromate  mor- 
dant, violet  shades,  and  if  used  in  more  concentrated  form, 
black. 

A  beautiful  dark  brown  for  Thibet  or  wild  goat  is  obtained 
as  follows :  Mordant;  40  grammes  potassium  bichromate  and 
20  grammes  cream  of  tartar  to  10  litres  of  water  ( 12  hours)  ; 
rinse  well  and  dye  for  24  hours  in  a  bath  made  up  of  follow- 
ing proportions :  5  grammes  Ursol  D,  5  grammes  pyrogallic 
acid,  300  grammes  peroxide  of  hydrogen  ;  20  grammes  am- 
monia, 10  litres  water.  If  more  rapid  action  is  desired,  'a 
stronger  dye  liquor  is  used,  viz.,  20  grammes  Ursol  D,  10 
grammes  pyrogallic  acid,  750  grammes  peroxide  of  hydrogen, 
20  grammes  ammonia,  10  litres  water.  With  the  latter  form- 
ula, the  time  required  for  dyeing  is  reduced  to  hours. 

A  grey-brown  for  wild  goat  is  produced  by  mordanting  with 
bichromate — cream  of  tartar  and  dyeing  out  with :  Ursol  D,  I 
32 


498 


THE  MANUFACTURE  OF  LEATHER. 


gramme;  Ursol  P,  I  gramme;  pyrogallic  acid,  I  gramme;  per- 
oxide of  hydrogen,  100  grammes;  ammonia,  10  grammes; 
water,  10  litres.    Leave  in  dye  liquor  12  hours. 

Light  brown  for  long-haired  musk-ox:  A  solution,  per  litre 
of  water,  of  Ursol  P,  10  grammes  ;  Ursol  D,  8  grammes  ;  pyro- 
gallic acid,  IO  grammes;  peroxide  of  hydrogen,  100  grammes, 
and  ammonia,  8  grammes,  is  made  by  first  adding  the  two 
Ursols  in  a  heated  state ;  then  the  peroxide  of  hydrogen  and 
pyrogallic  acid,  and  lastly,  when  all  the  other  ingredients  have 
been  incorporated,  the  ammonia.  No  mordanting  is  necessary, 
and  the  dye  is  applied  with  a  brush  and  allowed  to  dry. 

Imitation  of  seal-skin  in  clipped  musk-ox :  For  mordant,  use, 
as  heretofore,  potassium  bichromate  and  cream  of  tartar,  and 
color  with  a  solution  of  8  grammes  Ursol  P,  6  grammes 
Ursol  D,  5  grammes  pyrogallic  acid,  125  grammes  peroxide 
of  hydrogen,  and  5  grammes  ammonia  to  1  litre  water.  When 
dry,  clean  thoroughly,  and  apply  with  a  brush  to  the  tips  of 
the  hair  a  dye  of  10  grammes  Ursol  D  and  250  grammes  per- 
oxide of  hydrogen  to  1  litre  of  water.  In  about  an  hour  the 
tips  of  the  fur  will  show  black  and  a  strikingly  deceptive  imi- 
tation of  seal-skin  is  the  result. 

Imitation  nutria  in  clipped  rabbit:  Apply  with  a  brush,  a 
solution  of  12  grammes  Ursol  P,  8  grammes  Ursol  D,  6 
grammes  pyrogallic  acid  and  100  grammes  peroxide  of  hydro- 
gen, to  1  litre  of  water. 

Intense  black  for  Angora  goat  or  other  similar  skins :  Mor- 
dant with  20  to  30  grammes  potassium  bichromate,  and  10  to 
15  grammes  cream  of  tartar  to  10  litres  water  ( 12  hours).  The 
use  of  a  more  powerful  mordant  is  not  advisable,  as  it  imparts 
a  brownish  tinge  to  the  black.  Rinse  well  and  dye  out  with  : 
30  grammes  Ursol  D,  1  litre  peroxide  of  hydrogen,  in  10  litres 
of  water.  Twelve  hours  will  bring  out  the  desired  color.  A  like 
proportion  of  sulphate  of  iron  or  sulphate  of  copper  may  be 
substituted  for  the  potassium  bichromate  in  the  mordanting 
liquor,  and  the  former  will  also  be  found  very  effective. 

Ursol  DB  is  especially  useful  in  producing  a  blue-black  tinge, 


TANNING  AND  DYEING  FURS  AND  HAIR-SKINS.  499 


but  in  this  case  the  potassium  bichromate  mordant  must  be  re- 
placed by  one  of  sulpate  of  iron  and  cream  of  tartar,  or  sulphate 
of  copper  and  cream  of  tartar,  or  a  mixture  of  the  two  sulphates 
and  cream  of  tartar,  which  all  give  excellent  results. 

Directions  for  producing  a  blue-black  tinge  are — Mordants  : 
I.  20  grammes  sulphate  of  iron  and  10  grammes  cream  of  tar- 
tar to  10  litres  water  (12  hours)  ;  II.  20  grammes  sulphate  of 
copper  and  1 0  grammes  cream  of  tartar  to  1  o  litres  of  water  ( 1 2 
hours)  ;  III.  15  grammes  sulphate  of  iron,  5  grammes  sulphate 
of  copper  and  10  grammes  cream  of  tartar  to  10  litres  water 
(12  hours).  Dye  out  with:  20  grammes  Ursol  DB  and  500 
grammes  peroxide  of  hydrogen  to  10  litres  water  (10  to  12 
hours). 

When  mordant  I.  is  used  the  resulting  black  has  a  deep-blue 
tinge,  and  the  skin  itself  remains  a  light  blue.  Mordant  II. 
gives  an  intense  black,  while  the  skin  also  becomes  black.  By 
using  mordant  III.  the  skin  remains  lighter  than  is  the  case  in 
either  of  the  foregoing  recipes,  without,  however,  interfering 
with  the  desired  tinge  of  the  fur. 

When  the  dye-bath  is  to  be  used  over  again,  its  strength  may 
be  replenished  by  the  addition  of  a  proportion  of  about  60  per 
cent,  of  the  quantities  used  in  the  original  liquor. 

A  peculiar  advantage  in  dyeing  with  Ursol  colors  is  their 
great  coloring  energy,  which  is  especially  noticeable  when  the 
dye  is  applied  with  a  brush  to  the  tips  of  the  hair,  or  used  to 
give  a  streaked  appearance.  For  example,  a  single  application 
of  a  solution  of  about  15  grammes  of  Ursol  D  and  100  grammes 
peroxide  of  hydrogen  to  one  litre  water,  will  be  found  sufficient 
to  tip  a  fur  with  black  or  to  tint  lightly. 

The  appliances  required  for  practical  dyeing  by  the  processes 
above  described  are :  A  boiler  for  heating  water,  several  small 
vats,  or  sawed-in-half  petroleum  barrels  to  contain  the  mordant- 
ing and  dye  liquors,  some  racks  on  which  to  hang  up  the  wet 
skins,  an  airy  drying-room  capable  of  being  heated  in  cold 
weather,  and  finally  an  arrangement  for  rinsing,  so  that  fresh 
water  for  that  purpose  may  always  be  at  hand.    After  each 


500 


THE  MANUFACTURE  OF  LEATHER. 


operation  the  tubs  or  vats  containing  the  liquors  are  covered 
over  with  wooden  lids. 

IMPROVEMENTS  RELATING  TO  THE  MANUFACTURE  OF  ARTIFICIAL  FUR,  BEAVER 
AND  NUTRIA — J.  BIERMAN,  BERLIN,  GERMANY. 

Lamb  skins  are  placed  in  a  soap  and  water  bath  and  then 
pressed  out  and  brushed  with  a  color  solution  prepared  by  dis- 
solving i  part  by  weight  of  Ursol  D  (paraphenylene-diamine),  2 
parts  by  weight  of  Ursol  P  (paramidophenol),  I  part  by  weight 
of  pyrogallol,  50  parts  by  weight  of  hydrogen  dioxide,  and  4 
parts  of  ammonia  in  hot  water,  and  diluting  to  the  desired  tint 
with  cold  water.  After  drying,  the  hair  of  the  skins  is  combed 
with  a  wire  comb,  and  a  silky  gloss  is  produced  by  ironing 
with  acid.    Beaver  and  nutria  imitations  are  thus  prepared. 

WEIGHTS  AND  MEASURES  USED  IN  THIS  CHAPTER. 

Kilogram  (kilo),  metric  =    2.2046  pounds. 
Liter,  "      —    1.056  quarts. 

Gram,  "      =  15.432  grains. 


CHAPTER  XXXVI. 


TAWING  LAMB  AND  KID  SKINS  FOR  GLOVE  LEATHER, 
DYEING,  ETC. 

KlD  gloves  are  made  principally  from  lamb  and  kid  skins 
imported  from  Brazil,  France  and  Germany.  They  come  to 
this  country  packed  in  bales  containing  from  250  to  400  skins. 
In  preparing  the  material  for  gloves,  the  skins  have  to  pass 
through  a  number  of  processes  such  as  washing,  unhairing,  pad- 
dling, tanning,  staking,  coloring,  and  polishing.  The  skins, 
which  are  about  four  feet  in  length  and  about  three  feet  in 
width,  are  first  placed  in  wooden  tubs  and  thoroughly  soaked 
in  cold  water.  From  6co  to  800  skins  are  placed  in  each  tub 
and  left  to  soften  for  from  one  to  two  days,  according  to  the 
season.  From  the  soaking  tubs  they  are  placed  in  a  circular 
revolving  drum  and  washed.  This  drum  is  about  eight  feet  in 
diameter  and  about  four  feet  in  width  and  revolves  at  the  rate 
of  about  sixty  revolutions  per  minute.  A  number  of  wooden 
pins  connected  on  the  interior  of  the  apparatus  shift  the  skins 
about  as  it  revolves,  so  that  the  stream  of  water  which  passes 
in  at  the  center  of  the  drum  thoroughly  saturates  and  frees 
them  from  dirt. 

After  washing  for  a  quarter  of  an  hour,  they  are  taken  out 
and  placed  in  lime  pits.  These  pits  are  about  eight  feet  in 
depth,  eight  feet  in  length,  and  about  five  feet  in  width.  From 
800  to  1000  skins  are  placed  in  each  of  these  pits  and  are 
covered  with  lime  and  water  for  about  two  weeks.  The  lime 
acts  on  the  pores  of  the  skin,  opening  them  so  that  the  hair  can 
be  easily  removed.  The  skins  are  taken  from  the  pits  by 
means  of  long-handled  tongs.  To  take  off  the  excess  of  lime, 
the  skins  are  paddled.    This  is  performed  by  placing  the  skins 

(501  ) 


502 


THE  MANUFACTURE  OF  LEATHER. 


in  cold  water  and  running  them  back  and  forth  over  a  paddle- 
wheel.  This  wheel  is  about  three  feet  in  diameter,  about  six 
feet  in  length,  and  travels  at  the  rate  of  about  40  revolutions 
per  minute.  After  paddling,  the  hair  is  removed  by  spreading 
the  skins  out  over  a  beam,  an  operator  then  scraping  off  the 
hair  by  means  of  an  unhairing  knife. 

A  good  workman  can  unhair  about  20  skins  per  hour.  The 
next  operation  is  fleshing.  A  skin  is  placed  as  before  over  a 
beam,  the  operator  cutting  off  the  particles  of  flesh  adhering  to 
the  skin,  giving  it  an  even  thickness,  and  also  trimming  off  the 
ragged  ends.  The  scraps  are  sold  to  glue  makers,  and  the  hair 
to  plaster  and  carpet  manufacturers.  About  20  skins  can  be 
fleshed  per  hour.  After  fleshing  the  skins  are  washed  again 
in  the  revolving  drum  for  half  an  hour,  after  which  they  are 
fleshed  again  to  take  off  the  grease.  The  material  is  then 
paddled  again  in  warm  water,  after  which  the  skins  are  spread 
out  again  on  beams  and  slated,  the  process  taking  off  the  sur- 
plus dirt  and  giving  them  a  finish.  They  are  then  paddled  and 
then  drenched  in  a  tub  of  bran  and  water.  About  800  skins 
are  placed  in  the  drench  tub  at  a  time,  and  paddled  for  12 
hours,  the  operation  removing  the  lime  and  opening  the  pores 
of  the  skins.  The  skins  are  then  put  into  a  revolving  drum 
containing  a  tanning  liquor  composed  of  alum,  salt,  flour,  and 
the  yolks  of  eggs.  After  revolving  in  this  drum  for  twelve 
hours  at  the  rate  of  80  revolutions  per  minute,  the  skins  are 
taken  out  and  hung  up  on  hooks  in  a  drying  room  in  a  temper- 
ature of  1  io°  F.  for  twenty-four  hours. 

When  the  skins  are  dry,  they  are  dampened  with  water  and 
put  into  a  mill  and  softened.  This  mill  consists  of  two  per- 
pendicular swinging  planks  suspended  from  the  ceiling,  con- 
nected to  the  bottom  ends  of  which  are  large  wooden  blocks, 
which  move  back  and  forth  when  the  apparatus  is  in  motion. 
The  dried  skins  to  the  number  of  50  or  more  are  placed  on  the 
floor  of  the  mill  in  front  of  the  blocks,  which,  as  they  move 
forward,  squeeze  and  press  them  together  until  they  become 
soft,  after  which  they  ,are  staked.    This  is  performed  by  draw- 


LAMB  AND  KID  SKINS. 


503 


ing  the  skins  back  and  forth  over  the  edge  of  a  broad  steel 
knife,  about  18  inches  in  length  and  about  8  inches  in  width. 
After  this  operation,  which  also  softens  the  material,  they  are 
put  again  into  the  drying  room,  after  which  they  are  staked 
again,  the  operation  taking  off  the  dried  flour,  which  sticks  to 
the  material  from  the  tanning  liquid. 

The  white  skins  are  then  packed  away  for  a  few  months  to 
ripen  for  working  purposes.  The  skins  are  then  selected  out 
for  coloring,  being  first  washed  in  a  drum  of  cold  water  for  20 
minutes,  after  which  they  are  placed  in  a  revolving  bath  of  egg 
yolk  for  twenty-four  hours,  which  softens  and  makes  the  stock 
pliable.  The  skins  are  then  colored.  A  skin  is  first  slicked 
out  smooth  on  a  lead  covered  table  and  given  a  wash  of  potas- 
sium bichromate  and  soda  ;  the  solution  preparing  the  skin  so 
that  it  will  take  the  coloring  ingredients.  The  gloves  are 
colored  in  black,  drab  and  tan,  iron  sulphate  being  used  to  pro- 
duce black,  zinc  sulphate  for  drab,  and  sulphate  of  alum  for  tan 
color. 

The  coloring  ingredients  are  poured  on  the  skins  with  a  cup 
and  rubbed  with  a  brush.  The  skins  are  then  dried  and 
staked  again,  and  then  polished  over  a  flannel  covered  wheel. 
The  raw  skins  cost  now  (August,  1897)  from  $7  to  $9  per 
dozen.* 

BLACK  ON  GLOVE  SKINS. 

771  grains  logwood  extract  and  154  grains  fustic  extract  are 
dissolved  in  one  quart  of  water  ;  the  leather  is,  at  99  degrees  F., 
brushed  five  times  with  this  liquor.  Next  154  grains  chromate 
of  potash  and  77  grains  sulphate  of  copper  are  dissolved  in  one 
quart  of  water,  and  the  leather  is  brushed  twice  with  this  solu- 
tion ;  after  it  has  been  absorbed,  the  leather  is  brushed  another 
time  with  the  logwood  solution.  When  half  dry,  it  is  to  be 
rubbed  with  aqua  ammonia  (154  grains  per  quart  of  water), 
using  a  woolen  cloth ;  it  is  brushed  afterwards  with  water,  and 
then  treated  with  yolk  of  egg  and  glycerine. 


*  The  Scientific  American. 


THE  MANUFACTURE  OF  LEATHER. 


Another  black  for  glove  leather  is  prepared  as  follows :  In 
two  gallons  of  water  heated  to  1150  or  1200  F.,  dissolve  two 
ounces  logwood  extract  and  two  and  a-half  drachms  of  fustic. 
In  another  vessel  dissolve  two  and  a-half  drachms  bichromate 
of  potash  and  one  drachm  of  sulphate  of  copper  in  a  pint  and 
a-half  of  water.  The  first  liquor  is  used  to  rub  into  the  skin 
several  times.  The  second  liquor  is  the  blacking;  after  it  has 
been  applied,  another  coating  of  the  first  liquor  is  given. 
Finally  the  leather  is  washed  off  with  water  containing  am- 
monia, and  finished  as  usual.  For  other  colors  and  shades  on 
glove  leather  see  Chapter  on  Dyeing. 


CHAPTER  XXXVII. 


TO  PUT  A  GLOSS  ON  BLACK  LEATHER. 

THERE  are  seven  different  solutions  which  may  be  used  for 
putting  a  handsome  and  brilliant  gloss  on  black  leather,  and 
the  following  are  the  methods  for  manufacturing  them  : 

1.  Take  ten  parts  of  albumen,  and  dissolve  them  in  ninety 
parts  of  water.  Blood  albumen  is  the  best.  The  water  may 
be  either  cold  or  tepid,  but  its  temperature  must  never  be  more 
than  Jo°  F.,  or  the  albumen  will  not  dissolve.  White  cf  egg 
may  also  be  dissolved  in  its  weight  of  water.  The  solution  is 
put  on  by  means  of  a  soft  sponge.  Directly  afterward  the 
skins  must  be  hung  up  in  a  place  protected  from  the  dust 
and  sun. 

2.  A  solution  of  gum-lac.  Mix  up  together  in  a  litre  (l% 
pints)  of  water,  100  grammes  ($%  ounces)  of  borax,  and  200 
grammes  (7  ounces)  of  gum-lac,  and  boil  until  the  whole  is  en- 
tirely dissolved.  Then  add  200  grammes  (7  ounces)  of  negro- 
sine,  and  leave  it  to  cool.  The  solution  is  put  on  with  a  sponge. 

3.  Caseine  dissolved  in  ammonia.  Take  a  certain  quantity 
of  white  cheese  finely  ground  and  put  it  with  some  ammonia 
previously  dissolved  in  a  quantity  of  water  of  equal  weight. 
By  means  of  evaporation  a  substance  is  obtained  which  consti- 
tutes a  varnish  of  uncommon  richness. 

4.  Algine  dissolved  in  water  in  the  proportion  of  12  to  100. 

5.  China  moss  dissolved  in  water.    Boil  it  for  two  hours. 

6.  A  varnish  called  panclarite,  which  is  made  in  the  follow- 
ing manner:  Dissolve  100  grammes  (S}4  ounces)  of  soap  of 
rosin  and  900  grammes  (31^  ounces)  of  ordinary  glove  skin, 
finished  off  with  from  30  to  60  grammes  ( 1.05  to  2.1  ounces)  of 
glycerine.  When  the  solution  has  the  appearance  of  a  jelly, 
spread  it  over  the  skin  with  a  sponge. 

(505) 


506 


THE  MANUFACTURE  OF  LEATHER. 


7.  A  liquid  composed  of  the  following  ingredients  :  200  parts 
water,  4  parts  potash,  20  parts  carnauba  wax,  10  parts  sugar, 
10  parts  rosin,  5  parts  glycerine,  and  2  parts  aniline.  Boil  the 
mixture  for  half  an  hour,  and  add  200  parts  glove  gelatine.  Let 
it  cool  and  put  on  with  a  sponge. 

The  above  are  the  seven  newest  processes  for  putting  a  gloss 
on  black  leather.  The  processes  can  be  modified  so  as  to  in- 
clude glove  leather;  but  as  given  are  for  any  kind  of  black 
leather. 


CHAPTER  XXXVIII. 


SHEEP  LEATHERS. 

FEW  people  realize  the  importance  of  the  sheepskin  industry 
or  the  number  of  uses  to  which  sheepskins  are  put.  Last  year 
(1896)  at  Chicago  alone  there  were  received  3,406,739  head  of 
sheep,  of  which  number  2,932,093  head  were  slaughtered  at  the 
packing  houses.  The  skins  of  these  2,932,093  sheep  were  dis- 
posed of  for  various  purposes,  in  fact  more  than  the  average 
reader  has  any  idea  of.  We  have  been  able  to  obtain  a  portion 
of  the  uses  for  which  these  skins  are  suitable,  and  give  them 
herewith  as  follows :  The  greatest  demand  probably  comes 
from  shoe  manufacturers,  who  use  a  large  number  of  skins  an- 
nually in  making  up  cheap  shoes.  The  linings  and  uppers  of 
thousands  of  pairs  of  shoes  are  made  from  sheepskins,  although 
there  is  little  to  say  of  the  wearing  quality  of  shoes  whose 
uppers  are  wholly  composed  of  this  class  of  stock.  The  sec- 
ond largest  demand  comes  from  the  manufacturers  of  gloves 
and  mittens.  Many  a  pair  of  gloves  which  have  been  made 
from  sheepskins  are  sold  as  genuine  buckskin  gloves,  but  the 
demand  for  cheap  gloves  and  mittens  makes  it  possible  for 
manufacturers  to  palm  off  the  sheepskin  glove  for  something 
better  than  it  really  is. 

Next  in  order  comes  the  demand  from  the  bookbinders, 
who  consume  large  quantities  of  sheepskins  in  the  binding  of 
books.  The  manufacturers  of  satchels,  hand-bags  and  pocket- 
books,  use  very  large  amounts  of  skins,  in  fact,  we  dare  say 
that  the  bulk  of  these  goods  are  made  from  sheep  pelts.  Even 
the  better  class  of  these  goods,  which  are  not  made  wholly 
from  pelts,  are  lined  with  them.  To-day  there  are  less  of  these 
goods  made  from  sheepskins  than  formerly,  owing  to  the  lib- 

(5o7  ) 


508 


THE  MANUFACTURE  OF  LEATHER. 


eral  use  of  canvas,  which  takes  the  place  of  these  skins.  Con- 
tinuing the  list  we  find  the  following  articles  are  made  up  wholly 
of  the  skins  from  the  animal  with  the  "golden  hoof:  "  Saddle- 
pads,  harness,  boxing  gloves,  baseball  covers,  bindings  of  gun 
cases,  gussets  in  overalls,  binding  of  pockets  for  street-car  con- 
ductors, linings  for  hats  (which  takes  thousands  of  skins),  bel- 
lows, plasters,  children's  toys  of  almost  endless  variety,  imita- 
tion chamois  skins,  saddletrees  in  place  of  rawhide,  drum  heads, 
slippers,  leather  clothing,  catchers'  gloves,  heel  protectors, 
chair  seats  and  purses.  Heavy  skins  are  used  for  blacksmiths' 
aprons  and  command  a  good  price  for  large  sizes.  Skins  that 
have  the  wool  left  on  are  also  put  to  numerous  uses,  among 
which  we  mention  coats,  mats,  mittens,  gloves,  caps,  sleigh- 
robes,  boot-linings,  and  long  wool  dusters. 

The  cold  sweat  process  is  used  in  a  limited  extent  in  this 
country  for  unhairing  sheepskins  in  order  to  keep  the  wool  in 
a  clean  condition,  as  it  would  be  destroyed  by  contact  with 
lime  or  other  alkalies. 

Sodium  sulphide  is  an  agent  which  is  more  largely  used  for 
unhairing  sheepskins.  Sodium  sulphide,  when  mixed  with  the 
lime  during  the  slaking  process,  enters  into  chemical  combina- 
tion with  the  lime,  forming  varous  mixed  sulphides  which  have 
a  much  more  energetic  action  on  the  skin,  dissolving  out  all 
the  keratines,  but  not  swelling  the  skin  to  the  same  extent  as 
lime  alone;  the  addition  of  sodium  lessens  the  time  required  to 
lime  a  skin,  attacks  the  hair  and  weakens  it  or  dissolves  it,  ac- 
cording to  the  quantity  used.  It,  however,  produces  a  coarser 
grain  on  the  skin,  and  at  the  same  time  does  not  take  so  much 
out  as  lime  does  alone. 

Arsenic,  if  mixed  in  the  same  way,  also  forms  sulphides  and 
hydrosulphides  of  lime  and  arsenic,  which  also  have  a  more 
energetic  action  on  the  skin  than  lime  alone,  and  produce  simi- 
lar results  to  lime  and  sulphide  of  sodium,  but  give  a  finer 
grained  skin,  with  more  gloss. 

In  the  tanning  of  sheepskins  it  is  necessary  to  remove  the 
grease.    To  remove  grease  from  raw  sheepskins,  the  skins  after 


SHEEP  LEATHERS. 


509 


liming  are  usually  pressed  between  strong  presses,  hydraulic  or 
otherwise,  the  skins  being  sprinkled  with  sawdust  to  prevent 
them  from  slipping. 

For  raw  skins  or  limed  goods  the  pressure  method  appears 
the  simplest,  and,  being  very  effective,  the  best.  Sheepskins 
for  mats  with  the  wool  are  plastered  with  fuller's  earth  or 
whitening  on  the  flesh  and  put  in  a  hot  room,  a  process  very 
effective  for  this  particular  purpose. 

The  skins  are  then  bated.  The  object  of  bating  and  puring 
skins  is,  first  to  remove  all  lime  salts  contained  therein,  and, 
at  the  same  time,  to  rid  the  skins  of  the  hair  sacs,  coriin,  albu- 
men etc.,  and  to  dissolve  out  a  certain  amount  of  the  skin  sub- 
stance, rendering  the  leather  softer  and  more  pliable,  at  the 
same  time  to  partially  bring  down  the  substance  of  the  skin, 
which  has  been  unduly  swollen  by  the  previous  process  of 
liming.  Many  other  compounds  have  been  patented  as  substi- 
tutes for  hen  or  pigeon  excrement. 

Among  such  are  sulphuric  acid,  hydrochloric  acid,  the  Tiffany 
bate,  which  is  composed  of  glucose  and  stale  cheese,  ammonium 
chloride,  cresotinic  acid,  borophenol,  etc.  In  some  factories 
some  of  these  have  proved  very  succesful,  and  are  rapidly  gain- 
ing in  favor.  Some  experiments  have  been  made  with  using 
pure  cultures  of  the  various  bacteria  which  are  found  in  ordinary 
bates.    These  can  now  be  bought  on  a  commercial  scale. 

The  skins  are  then  ready  for  the  tanning  process,  but  their 
treatment  here  depends  upon  the  kind  of  leather  into  which 
they  are  to  be  made. 

Some  manufacturers  wash  the  skin  after  bating  in  warm 
water,  softened  with  borax  in  the  proportion  of  one  pound  of 
borax  to  the  100  gallons,  and  then  flesh  them;  but  as  previ- 
ously stated,  this  depends  upon  the  kind  of  leather  into  which 
the  skins  are  to  be  made. 

The  Vaughn  Machine  Co.,  Peabody,  Mass.,  build  a  shaving 
and  skiving  machine  for  sheepskins.  It  is  constructed  on  the 
same  principle  as  their  fleshing  machine ;  but  it  is  especially 
fitted  and  adapted  for  this  purpose.    The  machine  will  shave 


THE  MANUFACTURE  OF  LEATHER. 


the  stock  either  partly  or  fully  tanned,  clearly  and  evenly,  and 
without  tearing  or  scratches.  The  capacity  is  from  100  to  150 
dozens  per  day. 

IMITATION  CHAMOIS  LEATHER, 

Which  is  remarkable  for  its  soft  texture  and  porous  nature,  is 
prepared  by  the  action  of  oil  on  the  raw  skin.  Chamois 
leather  was  formerly  made  from  the  skins  of  sheep,  calf  and 
chamois  goat — hence  its  name.  Now,  however,  the  flesh  split 
of  ordinary  sheepskins  is  used.  The  skins  receive  a  thorough 
liming,  and  are  then  split.  The  flesh  split  generally  receives  a 
still  further  liming  in  order  to  remove  the  coriin  and  other  sol- 
uble matters  from  between  the  fibres.  The  fleshes  are  now  fre- 
quently subjected  to  a  bating  process,  and  a  short  bran  drench, 
which,  at  the  same  time,  secures  the  complete  absence  of  lime. 

After  the  usual  beam  work,  the  skins  are  pressed  or  hung 
out  to  remove  surplus  water,  and  while  still  moist  are  sprinkled 
with  oil  on  a  table  and  folded  in  cushions,  three  or  four  skins 
together,  and  are  stocked  for  two  or  three  hours,  shaken  out, 
and  hung  up  for  about  an  hour  to  cool  and  partially  dry. 
They  are  again  folded  in  bundles  and  stocked  for  a  short  time, 
taken  out,  re-oiled,  and  again  returned  to  the  stocks.  This 
process  is  repeated  until  the  skins  lose  their  original  smell  of 
lime,  and  acquire  a  peculiar  mustard-like  color,  and  the  water 
which  was  at  first  present  has  been  entirely  replaced  by  oil. 

When  the  oiling  is  complete,  the  skins  are  piled  in  heaps  on 
the  floor  or  in  boxes.  The  oxidation  of  the  oil,  which  has 
already  commenced  during  the  process  above  described,  is 
completed  by  a  process  of  fermentation  in  which  the  skins 
heat  very  considerably.  They  must  be  carefully  watched,  and 
if  the  heat  rises  so  high  as  to  endanger  the  quality  of  the 
leather,  the  pile  is  turned  over,  the  skins  being  turned  out  to 
cool,  and  then  put  back  into  pile.  When  this  fermentation 
process  ceases  and  the  skins  are  no  longer  susceptible  of  heat- 
ing, they  are  then  treated  to  remove  the  surplus  oil.  This  on 
the  Continent  is  done  by  throwing  the  skins  into  hot  water, 
and  wringing  or  squeezing  out  the  oil  (degras).    In  England, 


SHEEP  LEATHERS. 


511 


however,  the  oil  is  generally  removed  by  washing  the  skins 
with  soda  or  potash  lye.  The  partly  saponified  oil  which  is 
pressed  out  is  recovered  by  neutralization  with  sulphuric  acid, 
and  forms  the  sod  oil  of  commerce. 

The  finishing  process  consists  of  staking  during  drying  to 
retain  the  softness,  and  smoothing  the  flesh  on  the  fluffing 
wheel.  They  may  be  bleached  by  sprinkling  with  water  and 
exposure  to  the  sun,  or  by  treatment  with  a  weak  solution  of 
permanganate  of  potash,  and  subsequently  with  very  dilute 
sulphuric  acid,  or  may  be  treated  with  sulphurous  acid  in  gas- 
eous form.  (See  Chapter  XL.)  In  the  United  States  and' on 
the  Continent  of  Europe,  the  skins,  instead  of  being  laid  in 
piles  to  oxidize  and  ferment,  are  usually  hung  up  in  warm 
rooms.  This  is  much  less  dangerous,  and  produces  a  better 
color. 

WHITE  LEATHER. 

Glove  kid  or  calf  kid  or  white  sheep  leather  are  all  white 
leathers.  After  the  soaking  and  liming  of  the  skins,  which  is 
usually  done  by  pasting  them  on  the  flesh  side  with  a  mixture 
of  sodium  sulphide  or  arsenic,  they  are,  after  unhairing,  thor- 
oughly washed  in  water,  well  scudded  on  the  beam  to  get  dirt 
and  scud  out,  trimmed  and  then  pured  in  a  weak  pure,  about 
one  to  one  and  a  half  pails  of  paste  for  200  skins,  sufficient  to 
make  the  water  opaque,  but  not  soapy. 

After  puring,  the  skins  are  again  washed  and  worked  on 
both  flesh  and  grain,  and  are  then  drenched  for  from  six  to  ten 
hours.  The  skins  are  now  ready  for  tawing.  The  tawing 
paste  consists  generally  of  a  mixture  of  flour,  egg  yolk  or  egg 
preparation,  alum  and  salt.  This  may  be  done  in  a  drum,  or 
may  be  trodden  in  by  foot,  the  latter  process  being  the  Conti- 
nental one.  If  the  drum  is  used,  care  must  be  taken  that  the 
skins  are  not  allowed  to  get  too  hot  in  the  drum. 

After  tawing,  they  are  hung  up  in  a  cool  place  for  the 
paste  to  set,  dried  in  a  cool  place,  and  then  hung  for  a  few 
weeks  to  soften  and  absorb  moisture.  They  are  then  staked, 
fluffed  on  the  flesh,  and  are  now  ready  for  dyeing  or  finishing. 


512 


THE  MANUFACTURE  OF  LEATHER. 


CAPE  SHEEP. 

This  class  of  goods,  being  of  coarse  texture,  and  not  used 
for  the  finest  purposes,  the  ordinary  pit  process  is  usually  em- 
ployed. The  skins  are  unwooled  by  the  sweating  or  painting 
process,  and  then  further  limed  to  thoroughly  swell  the  goods. 
After  liming,  they  are  fleshed  and  scudded,  may  be  lightly 
pured  and  bran-drenched  after  working  on  the  beam  to  remove 
bran,  scud,  etc. 

The  goods  are  now  tawed  in  a  paddle  or  ordinary  pits,  with 
a  liquor  made  from  hemlock  or  other  common  bark.  The  tan- 
ning in  paddle  lasts  from  four  to  ten  days,  with  liquors  of  con- 
stantly increasing  strength  ;  if  in  pits,  the  process  takes  from 
two  to  four  weeks.  The  skins  are  now  lightly  oiled  on  the 
grain  with  fish  or  linseed  oil,  damped,  staked  and  re-dried. 

LINING,  BINDERS  AND  SKIVERS. 

The  manufacture  of  sheep-skins  into  linings,  bindings  and 
skivers  is  an  important  one.  The  sheep-skins  used  are  both 
domestic  and  foreign ;  those  derived  from  Great  Britain  are 
mostly  "  sheep-skin  fleshers,"  and  are  treated  with  vitriol  before 
shipment  to  preserve  them.  A  flesher  is  the  backside  of  a 
sheepskin.  They  are  first  milled  in  salt  and  water,  to  neutral- 
ize the  acid,  and  are  then  run  out  on  the  beam. 

The  materials  used  for  tanning  this  variety  of  leather  are 
usually  hemlock  bark,  oak  wood  extract,  sumach,  gambia,  and 
alum. 

These  skins  are  finished  in  all  colors ;  hemlock  is  used  for 
colors  darker  than  its  own,  sumac  is  employed  for  white  and 
fancy  colors,  and  alum  mostly  for  those  that  are  to  be  dyed 
black. 

The  sheep-skin  fleshers  are  split  from  the  sheep-skins  while 
in  a  state  of  pelt,  and  special  machines  are  required  for  this 
operation.  We  show  in  Fig.  126  an  exterior  view  of  a  sheep- 
skin tannery. 

The  processes  which  we  shall  first  describe  are  for  those 
skins  which  arrive  at  the  tannery  from  foreign  countries,  split, 
free  from  wool  and  which  are  pickled. 


SHEEP  LEATHERS. 


513 


Sometimes  these  skins  are  placed  in  clean  water  and  washed  ; 
but  they  are  not  uncommonly  removed  from  the  casks  in  which 
they  were  shipped  and  immediately  soaked  in  salt  and  water, 
worked  out  on  the  beam  and  placed  in  the  tanning  liquor, 
whether  it  be  hemlock,  sumac,  or  alum. 

In  hemlock  and  sumac  they  remain  about  ten  or  twelve  days, 
the  strength  of  these  liquors  being  gradually  increased  every 
thirty-  six  hours,  and  in  alum  the  skins  remain  for  a  much  shorter 
time.  After  being  tanned,  they  are  removed  from  the  vats  with 
a  hook  and  piled,  and  left  to  drain,  as  shown  in  Fig.  127. 

The  skins  are  then  carried  to  the  drying  lofts  and  each  one 
hung  upon  two  hooks,  but  so  placed  that  the  skins  do  not  touch. 

Fig.  128  shows  an  interior  view  of  a  drying  loft  in  a  sheep- 
skin tannery,  with  the  skins  hanging  upon  hooks  to  dry. 

After  being  dried  the  skins  are  removed  from  the  hooks  in 
the  drying  loft,  and  transferred  to  the  "  putting  out  depart- 
ment," where  they  are  wetted  and  tacked  to  boards  used  for 
putting  out.  After  this  operation  they  are  again  hung  up  in 
the  loft  to  dry,  and  then  carried  to  the  "finishing-room"  and 
finished  on  the  machines  employed  for  that  purpose  ;  but  if  they 
are  to  be  dyed,  they  are  carried  to  the  dye-house  and  colored 
in  various  hues,  aniline  colors  being  generally  employed. 

After  being  dyed,  the  skins  are  again  hung  up  in  the  lofts  to 
dry,  and  are  next  carried  to  the  finishing  department,  shown 
in  Fig.  129.  and  rolled,  glassed,  or  pebbled  by  machines  used 
for  the  purpose,  and  which  have  been  illustrated  and  explained 
in  detail  in  Chapter  XIX. 

After  being  finished  on  the  machines,  the  skins  are  meas- 
ured, marked  and  bundled  ready  for  market. 

DRESSING  SHEEP-SKIN  FLESHERS  FOR  GLOVE  BINDINGS,  ETC. 

The  following  process  for  dressing  "  sheep  skin  fleshers,"  to 
be  used  in  the  manufacture  of  gloves,  for  hidings,  etc.,  was 
patented  in  1875,  by  Richard  Hart,  of  Gloversville,  N.  Y.,  the 
patent  having,  however,  now  expired. 

The  quantity  of  the  mixtures  to  be  specified  is  intended  for 
33 


5<4 


THE  MANUFACTURE  OF  LEATHER. 


5i8 


THE  MANUFACTURE  OF  LEATHER. 


about  two  dozen  sheep-skin  fleshers  of  the  ordinary  size.  In 
carrying  out  the  process,  first  immerse,  pound,  and  stir  the  skins 
for  about  one-half  hour  in  a  fluid  mixture,  prepared  as  follows: 
Dissolve  one  pound  of  alum  in  one  and  a  half  gallons  of  water, 
which  is  readily  done  by  boiling.  Then  mix  in  a  separate 
vessel,  one-half  pound  each  of  flour  and  oatmeal,  or  one  pound 
of  either  alone,  with  one  gill  of  oil  and  one  and  a  half  gallons  of 
water,  and  mix  this  composition  with  the  alum-water.  At  the 
expiration  of  the  designated  time  take  the  skins  out  of  this  mix- 
ture and  stretch  them,  and  remove  the  ground  work  and  knife- 
marks  from  the  grain  side.  Then  immerse  them  for  about  the 
same  length  of  time,  and  with  the  same  manipulations  as  before, 
in  a  fluid  mixture,  prepared  as  follows:  One  gill  of  urine,  one- 
half  bar  of  bar-soap,  one-half  ounce  of  soda,  one-half  pound  of 
salt,  and  about  two  ounces  of  whiting  or  ochre,  all  boiled  in  one 
and  a  half  gallons  of  water  until  they  are  thoroughly  dissolved, 
to  which  are  added  one-half  pound  of  flour  and  one-half  pound 
of  oatmeal,  or  one  pound  of  either  alone,  mixed  in  one  and  a 
half  gallons  of  cold  water.  The  skins  are  then  dried,  stretched, 
and  staked  out,  and  can  now  be  faced  or  finished  upon  either 
side  in  the  usual  manner. 

Instead  of  urine  in  the  mixture  last  described,  a  small  quan- 
tity of  ammonia  may  be  used,  as  it  produces  the  same  effect; 
or  the  proportion  of  soda  may  be  suitably  increased,  or  lactic 
acid  maybe  used,  and  neither  urine  nor  ammonia  be  employed, 
and  still  the  desired  result  obtained. 

Skins  dressed  by  the  usual  method  can  be  finished  or  faced 
on  the  flesh  side  only,  and  have  a  rough  and  hard  surface  on 
the  grain  side,  besides  being  rough  and  stiff  in  texture. 

Skins  dressed  by  this  process,  by  treatment  to  both  mixtures, 
may  be  finished  on  either  or  both  sides,  and,  it  is  claimed,  are 
made  soft,  pliable,  and  with  elasticity  or  "  spread"  and  stronger 
in  texture,  without  becoming  rough. 

Skins  which  are  treated  to  the  first  mixture  only  may  be  at 
once  dried,  staked,  and  stretched,  and  finished  on  either  or  both 
sides  in  the  usual  manner,  without  subjecting  them  to  the 


» 


SHEEP  LEATHERS. 


519 


second  mixture,  and,  it  is  claimed,  will  then  be  better  in  quality, 
and  have  a  susceptibility  of  better  finish,  than  skins  dressed  in 
the  ordinary  way;  but  it  is  preferable  to  employ  the  entire 
process  in  dressing  skins,  as  they  are  thus  given  a  superior 
quality  and  a  capacity  for  higher  finish  than  when  the  first  part 
of  the  process  only  is  used,  and,  when  finished,  bear  a  close 
resemblance  in  texture  and  quality,  to  deer-skin  or  castor. 

manasse's  method  for  tawing  sheep-skins. 

In  1875  Emanuel  Manasse,  of  Napa,  California,  patented  the 
following  process  for  tawing  sheep-skins: 

The  skins  are  taken  from  the  sweat-house,  and,  after  being 
properly  treated  in  the  beam-house,  are  immersed  in  a  solution, 
composed  for  two  hundred  skins,  of  the  following  ingredients: 

No.  1.  Twenty  pounds  of  salt,  thirty  pounds  of  white  rock 
potash,  three  hundred  gallons  of  water. 

The  skins  remain  in  this  solution  for  about  two  hours,  and 
are  then  wrung  out  dry,  and  immersed  in  a  solution  composed 
as  follows : 

No.  2.  Twelve  pounds  of  hard  soap  and  two  gallons  of  neat's 
foot  oil  in  one  hundred  and  fifty  gallons  of  water. 

After  being  kept  in  this  solution  long  enough  to  wet  them 
through,  the  skins  are  removed  and  hung  up  to  dry,  and  are 
wet  and  dried  in  this  manner  two  or  three  times. 

After  being  thus  treated  and  properly  tawed,  they  are  put 
in  a  dry  state  into  clear  water,  and  washed  in  a  thorough  man- 
ner to  remove  all  foreign  matter  from  them,  and  in  this  moist 
condition  are  dried  to  produce  leather  of  various  colors,  or,  if 
a  white  leather  is  required,  they  are  allowed  to  dry  without 
further  treating. 

The  proportions  of  the  ingredients  given  above  may  be 
changed,  as  the  nature  of  the  skins  requires,  without  affecting 
the  process. 

It  is  claimed  that  the  skins  thus  treated  combine  the  qualities 
of  softness,  pliability,  and  toughness,  which  allow  the  leather  to 
be  sewed  together,  as  in  the  manufacture  of  gloves  and  like 
articles,  without  tearing  or  allowing  the  stitches  to  pull  out. 


520 


THE  MANUFACTURE  OF  LEATHER. 


HIBB^RD  S  PROCESS  FOR  PREPARING  AND  TANNING  SHEEPSKINS. 

Hibbard's  process  for  preparing  and  tanning  sheepskins  for 
linings,  binders,  etc.,  is  as  follows  : 

To  remove  the  hair,  mix  the  following  composition  with 
water  sufficient  to  make  a  thick  paste,  apply  it  to  the  flesh  side 
of  the  hides,  fold  the  skins  and  keep  them  at  a  temperature  of 
summer  heat.    In  a  few  hours  they  are  ready  to  pull. 

Quicklime  (freshly  slacked)   'o  bushel. 

Wood  ashes   %  " 

Salt     3  pints. 

For  the  liming  process  use  the  same  composition,  mixed 
with  sufficient  water  in  a  vat  to  immerse  the  number  of  skins 
proposed  to  be  limed.  One  bushel  is  equivalent  to  one  bushel 
of  lime  alone.    The  liming  is  done  at  the  temperature  of  6o°  F. 

For  tanning  six  dozen  full  sized  sheep,  deer,  goat,  or  similar 
skins,  prepare  the  following  composition  : 

Salt   1 8  lbs. 

Sulphuric  acid   2  " 

Sumac  or  quercitron  bark   36  " 

Hydrochloric  acid   2  ounces. 

Dried  clover   18  lbs. 

Water   125  galls. 

Exhaust  the  sumac  or  bark  by  water,  add  the  salt,  enough 
to  insure  perfect  solution,  then  add  the  acids  and  incorporate 
by  stirring. 

hesthal's  process  for  dressing  sheep-skins,  etc. 

The  following  process  was  patented  in  1883,  by  August 
Hesthal,  of  San  Francisco,  Cal.,  and  is  useful  in  the  prepara- 
tion of  leather  for  button-pieces,  linings,  stays,  and  other  small 
articles. 

The  process  is  especially  applicable  to  sheep,  lamb,  kid,  and 
deer-skins.  The  skins  after  having  passed  through  the  sweat- 
ing process  and  been  properly  treated  in  the  beam-house,  are 
placed  in  a  solution  which  we  will  call  No.  i,  composed  of  two 


SHEEP  LEATHERS. 


521 


pounds  of  caustic  soda,  one  pound  of  borax,  and  sufficient 
water  to  cover  the  skins — say  one  hundred  gallons. 

The  skins  and  compound  are  contained  in  a  suitable  drum, 
in  which  they  are  run  for  a  half  hour  and  then  removed  and 
hung  up  to  dry. 

They  are  then  immersed  in  a  solution  which  we  will  call 
solution  No.  2,  composed  of  five  pounds  of  hard  soap,  one 
gallon  of  straits  oil,  one-half  pound  caustic  soda,  and  seventy- 
five  gallons  of  water. 

In  this  solution  they  remain  long  enough  to  become  soft  and 
wet  through,  after  which  they  are  put  into  a  drum  with  a  part 
of  the  composition  No.  2,  and  run  for  about  a  half  hour,  being 
then  removed  and  dried  as  before. 

They  are  next  softened  in  the  composition  No.  2,  and  then 
allowed  to  drip. 

They  are  then  again  placed  in  the  drum  with  a  solution  which 
we  will  call  No.  3,  and  run  for  about  a  half  hour ;  then  put  back 
into  the  composition  No.  2  and  soaked  for  one  hour,  and  then 
taken  out  and  hung  up  to  dry,  after  which  they  are  soaked  and 
dried  in  this  manner  two  or  three  times  in  composition  No.  2 
until  they  are  properly  prepared,  as  some  skins  may  need  to 
have  this  part  of  the  process  repeated  a  greater  number  of 
times  than  others.  After  the  skins  are  treated  in  this  manner 
and  have  become  leather,  they  are  put  in  a  very  weak  solution 
of  composition  No.  2,  in  order  to  thoroughly  soften  them,  and 
in  this  wet  condition  they  are  dyed  in  different  colors  ;  or,  if 
white  leather  is  required,  they  are  allowed  to  dry  without 
further  treating.  In  this  manner  is  produced  a  leather  which 
is  strong  and  pliable,  and  when  sewed  together  it  does  not 
crack,  nor  do  the  stitches  pull  out;  and  as  the  skins  are  pre- 
pared without  the  employment  of  lime  and  sulphuric  acid,  it 
leaves  the  fibres  in  their  natural  state  and  strength. 

The  proportions  of  the  ingredients  given  in  the  above  solu- 
tions, Nos.  I,  2  and  3,  are  estimated  for  about  one  hundred 
and  twenty  sheep-skins. 


522 


THE  MANUFACTURE  OF  LEATHER. 


COLORING  FOR  FIVE  DOZEN  SHEEP  SKINS. 

BLUE-REDDISH. 

Preparation  of  the  Skins  for  the  Dye  Bath. — Fill  a  tub  with 
15  pailfuls  of  warm  water;  to  this  add  1%  lbs.  sal  soda.  After 
it  is  dissolved,  take  the  five  dozen  skins  and  put  them  in, 
pounding  them  for  five  minutes ;  then  take  them  out  and  place 
them  in  a  tub  containing  15  pailfuls  of  warm  water,  pounding 
them  for  four  minutes.  Take  skins  out,  fill  a  tub  with  15 
bucketfuls  of  cold  water,  add  to  the  same  1  ]/2  pints  oil  of 
vitriol ;  stir  it  well ;  put  the  five  dozen  skins  in  it  and  handle 
them  for  five  minutes.  This  done,  withdraw  them  and  place  in 
a  tub  of  cold  water,  letting  them  remain  ten  minutes.  After 
this,  fold  them  together. 

Dyeing. — Fill  a  dye-box  with  ten  pailfuls  of  warm  water;  to 
this  add  1  oz.  blue-reddish  aniline,  which  has  been  previously 
boiled  one  minute  in  half  a  pail  of  water  and  half  a  tumblerful 
of  oil  of  vitriol. 

To  the  dye-box  add  half  a  tumblerful  of  oil  of  vitriol.  Put 
one  dozen  of  the  folded  skins  in,  handle  them  very  quickly  for 
three  or  four  minutes ;  then  take  them  out  and  wash  them  in 
cold  water.  For  every  other  dozen  add  to  the  box  ^  oz. 
blue-reddish  aniline  and  half  a  tumblerful  of  oil  of  vitriol. 
Warm  the  liquor  in  the  box  ;  color  the  rest  like  the  first. 

BLUE-BLUISH. 

The  same  preparation  of  the  skins  for  the  dye  bath  as  blue- 
reddish.  After  skins  are  folded,  fill  a  dye-box  with  four  pail- 
fuls of  warm  water.  Add  to  the  same  1  oz.  reddish-brown 
aniline.  This  must  first  be  added  to  a  half  bucketful  of  water 
and  boiled  three  or  four  minutes.  Put  one  dozen  of  the  folded 
skins  in  the  dye- box  and  handle  them  four  times  forward  and 
back.  Then  take  them  out  and  wash  them  in  cold  water. 
For  every  other  dozen  warm  the  liquor  up,  and  add  1  oz. 
reddish-brown  aniline. 


SHEEP  LEATHERS. 


523 


COCHINEAL. 

The  same  preparation  of  the  skins  for  the  dye  bath  as  blue- 
reddish.  Fill  a  box  with  three  to  four  pailfuls  of  milk-warm 
water;  add  to  this  2  ozs.  borax,  dissolved  in  2  quarts  boiling 
water.  Take  I  dozen  folded  skins  and  handle  them  twice  for- 
ward and  back ;  then  take  them  out,  and  add  for  every  other 
dozen  skins  2  ozs.  borax  dissolved  in  half  a  pailful  of  boiling 
water.  Let  the  skins  remain  in  the  borax  over  night.  Fill  a 
vessel  with  12  pailfuls  of  boiled  water;  add  to  the  same  ^  lb. 
turmeric  and  2l/2  lbs.  fine  ground  cochineal.  Let  this  boil  20 
minutes.  Add  to  the  same  liquor  5  ozs.  pearlash  and  3  ozs. 
alum,  and  boil  3  minutes  longer.  Of  the  boiled  liquor,  put  in 
a  dye-box  four  pailfuls.  Place  thirty  skins  one  by  one  in  the 
liquor.  After  this  add  two  pailfuls  of  cochineal  liquor  to  this 
dye-box  ;  put  the  skins  in  it  and  handle  them  twenty  minutes 
forward  and  back ;  then  take  them  out.  Color  the  rest  as  the 
first. 

LEMON  YELLOW. 

Same  preparation  of  the  skins  for  the  dye  bath  as  blue- 
reddish.  After  skins  are  folded,  fill  a  dye  box  with  four  pail- 
fuls of  warm  water.  Add  to  the  same  3  ozs.  picric  acid  dis- 
solved in  one-third  of  a  pailful  of  boiling  water.  To  the  same 
box  add  half  a  tumblerful  of  oil  of  vitriol.  Stir  it  well,  bring 
one  dozen  of  the  folded  skins  in  and  handle  them  very  quickly 
four  or  five  minutes.  Take  them  out  and  wash  in  cold  water. 
For  every  other  dozen  skins  warm  the  liquor  in  the  dye  box 
and  add  to  same  \  l/2  ozs.  picric  acid.  Color  the  rest  as  the 
first. 

GRASS  GREEN. 

Preparation  of  the  Skins  for  the  Dye  Bath. — Fill  a  tub  with 
15  pailfuls  of  warm  water,  add  1^  lbs.  sal  soda.  After  it  is 
dissolved,  take  the  five  dozen  skins  and  pound  them  five 
minutes;  take  them  out  and  fill  a  tub  with  15  pailfuls  of  warm 
water.  Put  them  in  and  pound  them  four  minutes.  Take  out 
and  put  them  in  a  tub  of  warm  water.  Let  them  remain  IO 
minutes.    After  this  fold  the  skins. 


524 


THE  MANUFACTURE  OF  LEATHER. 


Dyeing. — Fill  a  dye  box  with  4  pailfuls  of  warm  water,  add 
to  the  same  2  ozs.  bichromate  of  potash  dissolved  in  half  a  pail- 
ful of  boiling  water.  To  the  box  add  half  a  pint  chemical  blue. 
Stir  it  well,  and  put  one  dozen  of  the  folded  skins  in  it,  and 
handle  very  quickly  four  or  five  minutes.  Take  them  out  and 
wash  them  in  cold  water.  For  every  other  dozen  skins  warm 
the  liquor  up  in  the  dye  box;  add  to  the  same  1  oz.  of  bichro- 
mate of  potash,  dissolved  in  one-third  of  a  pailful  boiling  water. 
To  the  box  add  one-third  pint  chemical  blue.  Stir  it  well  and 
color  all  the  skins  like  the  first  dozen. 

CLARET  OR  MAROON. 

Same  preparation  of  the  skins  for  the  dye  bath  as  grass 
green.  Fill  a  vessel  with  15  pailfuls  of  water,  add  to  the  same 
in  a  bag  25  lbs.  logwood.  Let  this  boil  two  hours;  take  the 
bag  out.  Put  in  a  box  7  pailfuls  of  warm  water,  add  to  same 
\y2  lbs.  alum  dissolved  in  half  a  pailful  of  boiling  water.  Take 
30  of  the  folded  skins,  place  them  in  it,  and  handle  them  three 
times  forward  and  back.  Take  them  out,  and  fill  a  dye  box 
with  7  pailfuls  of  the  boiled  logwood  liquor.  Handle  the  skins 
four  times  forward  and  back,  take  them  out. 

If  a  darker  shade  is  wanted,  add  to  the  same  liquor  3  ozs. 
bichromate  of  potash  dissolved  in  half  a  pailful  of  boiling  water. 
Handle  the  skins  twice  forward  and  back.  After  this  wash  in 
cold  water. 

PINK. 

Same  preparation  of  the  skins  for  the  dye  bath  as  blue-red- 
dish. After  the  skins  are  folded,  fill  a  dye  box  with  four  pail- 
fuls of  milk-warm  water,  add  to  this  y  lb.  sal  soda,  dissolved  in 
one-third  pailful  of  boiling  water.  Handle  one  dozen  of  the 
folded  skins  in  it  twice  forward  and  back;  take  them  out,  add 
to  every  dozen  skins  y  lb.  sal  soda  dissolved  in  half  pailful  of 
boiling  water.  After  two  hours  fill  a  vessel  with  10  pailfuls  of 
water  (after  boiling);  add  to  same  \y  lbs.  cochineal.  Let 
this  boil  20  minutes,  then  add  to  the  same  \y  ounces  saleratus, 
I  y2  ounces  salts  of  tartar,  1  y2  ounces  cream  tartar,  2  ounces 


SHEEP  LEATHERS. 


525 


alum.  Let  this  boil  three  minutes  longer.  Take  this  boiled 
liquor,  put  three  pailfuls  in  a  dye  box,  and  handle  30  skins  one 
by  one  through  the  liquor.  After  this  add  two  pailfuls  from 
the  cochineal  liquor,  put  the  skins  in,  and  handle  them  15  min- 
utes forward  and  back,  then  take  them  out.  Color  the  rest  as 
the  first. 

SOLFERINO. 

Same  preparation  of  the  skins  for  the  dye-bath  as  blue-red- 
dish. Fill  a  dye  box  with  four  pailfuls  of  warm  water,  add  to 
same  1  oz.  fuchsine  dissolved  in  half  a  pailful  of  boiling  water. 
Take  1  dozen  of  the  folded  skins  and  handle  them  very  quickly 
three  or  four  minutes.  After  this,  take  them  out,  wash  them 
in  cold  water.  For  every  other  dozen  skins,  warm  up  the  liquor 
in  the  box,  and  add  to  same  ^£  oz.  fuchsine  dissolved  in  one- 
third  of  a  pailful  of  boiling  water.  Put  one  dozen  of  the  folded 
skins  in  and  handle  them  three  or  four  minutes.  Color  the 
rest  as  the  first. 

For  the  above  processes  of  dyeing  sheep  skins,  we  are  in- 
debted to  "Hides  and  Leather,"  of  Chicago,  and  for  some 
other  matter  in  this  chapter  we  are  indebted  to  the  answers 
made  to  technological  questions  by  candidates  at  the  examina- 
tions of  the  City  and  Guilds  of  London  Institute,  as  reported 
by  the  Leather  Trades  Circular  and  Review  of  London. 

DYEING  BARK-TANNED  SHEEPSKINS  INTENSE  DULL  BLACK. 

In  Switzerland  they  produce  an  even  mat-black  on  bark- 
tanned  sheepskins  by  washing  the  skins  thoroughly  and  put- 
ting them  in  a  sumac  bath.  To  100  skins,  according  to  size 
and  weight,  they  take  20  to  30  pounds  of  sumac  and  wheel  the 
skins  in  this  bath  two  or  three  hours,  then  wash  them  out  and 
on  the  table  or  in  the  machine  press  them  out,  slate  them  and 
stretch  them  on  frames  to  dry.  To  black  them  they  rub  them 
over  with  a  strong  decoction  of  logwood  with  a  small  addition 
of  aqua  ammonia;  this  makes  them  quite  dark;  they  are  then 
colored  with  a  good  vinegar  black.  After  the  skins  are  dry 
after  the  first  blacking,  they  are  again  rubbed  over  with  log- 
wood and  iron  black. 


CHAPTER  XXXIX. 


ELECTRIC  AND  OTHER  RAPID  TANNAGE  SYSTEMS. 

The  Groth  system  of  rapid  tannage  by  means  of  electricity 
has,  so  far,  been  demonstrated  in  the  United  States,  at  Kansas 
City,  Mo.,  where  good  results  are  claimed  for  it,  turning  out 
100  pounds  of  hides  in  six  weeks  without  the  aid  of  chemicals, 
extracts,  concentrated  or  heated  liquors.  Groth's  is-no-drum 
system,  the  ordinary  tan  pit  being  all  that  is  required  with  a 
light  wooden  frame  on  it  and  the  electric  plant.  This  system 
we  understand  has  not  been  a  success  in  Germany,  where  it  has 
been  tried  on  a  large  scale.  L.  A.  Groth,  Stuttgart,  Germany, 
is  the  name  and  address  of  the  inventor. 

One  inventor,  E.  Worms,  Paris,  France,  claims  to  hasten  the 
tanning  process  by  gradually  and  moderately  heating  the  hides 
and  the  liquor  within  a  closed  vessel  excluding  air,  and  at  the 
same  time  "  expelling  the  water  from  the  cells  of  the  hides  by 
electrically  decomposing  it."  The  hides  are  submerged  in 
water  in  a  rotating  drum,  and  a  tannin  extract  of  20°  B.  is  run 
in,  in  the  proportion  of  50  per  cent,  of  the  weight  of  the  hides, 
together  with  a  "vegetable  solvent"  amounting  to  "  5  per  cent, 
of  such  weight."  The  drum  is  closed  and  rotated.  When  the 
temperature  has  risen  to  590  F.,  an  electric  current  is  passed 
through  the  liquor  by  means  of  a  suitable  circuit,  the  tempera- 
ture being  maintained  by  its  means  at  770  to  86°  F.  When 
the  process  is  half  completed  the  circuit  is  broken  and  fresh 
tannin  is  introduced.  Light  hides  are  said  to  be  tanned  in  24 
to  48  hours,  heavy  hides  in  60  to  105  hours. 

Finot,  Ward,  Gaulard,  Meriten,  Crosse,  Rhodes  and  others, 
have  all  invented  processes  for  electric  tannage,  but  we  have 
heard  no  reports  of  their  general  employment. 

(  526  ) 


ELECTRIC  AND  OTHER  RAPID  TANNAGE  SYSTEMS.  527 


M.  C.  Dizer  &  Co.,  of  East  Weymouth,  Mass.,  who  operate 
a  tannery  in  conjunction  with  their  shoe  factory,  are  believers 
in  quick  tannage  and  are  making  experiments  constantly. 
Douglas  M.  Easton,  who  has  charge  of  the  tannery,  states  that 
in  the  past  six  months  they  have  tanned  by  his  special  2  la- 
bour process,  over  200,000  kangaroo  skins  and  6o,coo  wax 
calfskins.  They  are  developing  with  more  or  less  success  a 
quick  tannage  of  sole  leather,  and  claim  to  have  made,  with 
extract,  prime  leather  in  eight  hours.  They  have  also  been 
experimenting  with  the  chrome  process  on  sole  leather,  and  are 
to  build  an  addition  for  its  practical  operation. 

The  F.  Durio,  the  Velocitan,  and  many  other  processes  of 
quick  tannage  have  been  before  the  trade  for  some  time,  but 
we  have  heard  little  of  them  as  being  generally  successful. 

Mr.  S.  Kiis,  in  the  Oestercich-Ungarisches  Lederblatt  writes 
on  this  subject:  "With  the  various  patents  for  rapid  tannage 
which  are  published  almost  daily,  it  is  very  difficult  to  judge  of 
the  real  merits,  and  they  should  not,  as  they  are,  be  all  consid- 
ered as  being  one  and  the  same  thing.  Most  of  the  patents  of 
rapid  tannage  issued  lately  refer  to  mineral  tannage  with 
chrome  salts,  aluminates,  tin  and  other  metallic  salts,  and  are 
almost  exclusively  employed  for  the  tanning  of  light  small 
skins,  such  as  calf,  goat  and  sheep.  Their  value  does  not  de- 
pend upon  rapidity,  for  by  present  methods  the  tannage  is 
rapid  enough,  but  in  an  improvement  in  the  quality  of  the 
leather  produced.  So  that  when  rapid  tannage  is  spoken  of 
nowadays,  an  extra  rapid  tannage  in  one,  two  or  three  days  is 
meant.  Of  such  systems  as  this  there  are  but  few  known  or 
offered  for  sale.  We  refer  to  rapid  tannages  for  heavy  sole, 
harness  and  belting  leather.  These  systems  are  few,  and  of 
these  still  fewer  are  of  any  practical  value." 

The  past  two  years  have  witnessed  a  notable  revolution  in 
quick  tanning  processes.  And  the  revolution  has  been  on 
comparatively  new  lines.  Instead  of  trying  to  force  tannin  into 
the  hide,  the  latest  method  is  to  employ  chemicals  to  tho- 
roughly cleanse  the  hide  of  all  impurities,  thus  making  the 


528 


THE  MANUFACTURE  OF  LEATHER. 


texture  unusually  open  and  receptive  to  the  tannin.  Nor  is  the 
system  followed,  of  beginning  with  weak  vats  and  leading  up  to 
strong  liquors.  The  new  scheme  means  the  application  of 
strong  tan  liquors,  or  extract,  to  the  hides  or  skins  as  soon  as 
they  leave  the  beam  house.  Nor  are  the  hides  and  skins  laid 
away.  After  being  fleshed,  unhaired  and  drenched  they  are 
put  in  a  drum  with  extract  and  tanned  in  a  remarkably  short 
time.    But  leathers  tanned  in  this  way  lack  firmness  and  weight. 

Men  who  are  paying  attention  to  the  new  quick  tanning  pro- 
cesses, confidently  assert  that  good  sole  or  harness  leather  can 
be  made  in  ten  hours.  They  consider  thirty  hours  unusually 
long.  The  practical  tanners  who  are  investigating  the  promises 
of  the  new  tanning,  are  hopeful  that  something  has  been  dis- 
covered whereby  the  cost  of  the  leather  production,  particularly 
the  commoner  sort,  will  be  considerably  reduced.  By  the  new 
method,  extracts  can  be  used  exclusively,  and  tanneries  estab- 
lished in  any  part  of  the  country,  irrespective  of  the  nearness 
of  the  bark  supply. 

Many  good  processes  for  rapid  tannage  have  come  up,  but 
proved  too  expensive,  or  had  other  drawbacks,  and  were,  there- 
fore, neglected.  One  genius  many  years  ago  believed  he  could 
tan  leather  rapidly  by  forcing  liquors  through  the  hides  by  hy- 
draulic pressure.  This  idea  has  disappeared  in  company  with 
numerous  other  fads  and  notions  designed  to  help  tanners,  and 
gotten  up  usually  by  men  who  had  little  or  no  acquaintance 
with  practical  tanning. 

Taught  by  the  failure  of  others,  there  are  companies  now 
selling  to  tanners  quick  tanning  processes  that  have  merit 
enough  not  only  to  deserve  serious  consideration,  but  to  war- 
rant fair  trial.  The  owners  of  such  processes  do  not  make  any 
wild  claims.  Their  methods  of  doing  business  entitle  them  to 
attention  from  enterprising  men. 

It  will  occur  to  all  that,  as  quick-tanning  processes  come  to 
be  better  understood  and  more  generally  adopted,  the  some- 
what speculative  character  of  leather  manufacturing  will  be  less 
pronounced.    Manufacturers  of  shoes  and  other  leather  pro- 


ELECTRIC  AND  OTHER  RAPID  TANNAGE  SYSTEMS.  529 


ducts  have  a  great  advantage  over  tanners  in  the  fact  that  a 
comparatively  short  interval  occurs  between  the  purchase  of 
their  leather  and  the  sale  of  the  goods  made  therefrom.  Tan- 
ners, more  especially  those  making  sole,  harness,  belting  leath- 
ers, etc.,  have  to  wait  from  three  to  six  months  after  soaking  a 
batch  of  hides  before  the  latter  are  ready  for  market  as  finished 
leather. 

The  quick-tanning  processes  on  the  market  to-day  are  at- 
tracting attention  on  account  of  their  value  and  economy. 
Some  excellent  sole  leather  is  being  put  on  the  market  regu- 
larly each  week  in  the  United  States,  the  tanning  of  which  has 
been  accelerated  by  novel  methods.  Harness  leather  of  good, 
marketable  quality  has  been  made  in  eighteen  days.  The  time 
required  for  producing  upper  leather  has  been  reduced, 
although  this  is  due  largely  to  improved  methods  discovered 
by  the  tanners  themselves. 

It  must  be  admitted  that  tanners  are  somewhat  prejudiced 
against  testing  the  merits  of  new  processes.  It  is  doubtful  if 
there  is  a  tannery  in  existence  to-day  where  considerabe  money 
has  not  been  sunk  in  experiments.  This  of  itself  should  not  be 
an  insuperable  barrier  to  the  introduction  of  further  trials  and 
experiments.  Regulation  of  production  would  be  much  more 
easily  governed  if  leather  could  be  produced  in  comparatively 
short  time.  Less  capital  would  be  necessary  than  at  present, 
which  is  a  highly  important  item. 

Tanners  as  a  body  are  somewhat  suspicious  of  new  processes 
that  do  not  originate  in  their  own  plants.  Pressure  of  com- 
petition among  themselves,  however,  is  already  inducing  them 
to  look  with  more  favor  on  new  schemes  which  promise  well 
for  the  making  of  good  leather  at  reduced  cost  of  production. 
The  trouble  is  that  details  of  new  tanning  processes,  as  a  rule, 
are  so  rigidly  guarded  that  tanners  feel  somewhat  nervous 
about  agreeing  to  pay  for  something  about  which  they  are  kept 
in  the  dark.  The  inventors  of  rapid  processes,  on  their  part, 
would  be  at  the  mercy  of  the  tanners  if  they  consented  before- 
hand, without  promise  of  pay,  to  disclose  their  secrets.  On  the 
34 


53Q 


THE  MANUFACTURE  OF  LEATHER. 


whole  it  may  be  said  that  while  both  parties  to  transactions  are 
bound  to  take  fair  precautions  to  protect  themselves,  there  is 
such  a  thing  as  too  much  conservatism,  and  those  who  are 
willing  to  take  some  chances  are  more  likely  to  win  in  the  end 
than  their  less  courageous  brethren. 

The  bark  methods  of  tanning  are  passing  away  with  great 
rapidity,  extracts  and  chrome  are  taking  their  place,  and  in  the 
larger  establishments  the  chemist  has  become  an  invaluable 
part  of  the  personnel  of  the  tannery,  and  he  is  kept  busy  making 
investigations  and  suggestions. 

The  old-time  tanner  has  now  gone  the  way  of  his  fathers. 
It  is  now  certain  that  more  advanced  methods  will  be  used  by 
tanners  in  general  in  the  near  future,  or  a  new  and  different 
generation  of  leather  producers  will  step  forward  to  fill  the 
places  of  those  now  in  business. 

The  truth  is  that  the  average  tanner  has  been  too  conserva- 
tive for  his  own  interest,  but  new  blood  is  coming  to  the  front 
and  the  change  will  be  beneficial.  We  see  this  in  the  way 
modern  tanneries  and  currying  shops  are  being  built.  They 
are  fitted  out  with  all  the  latest  improvements  in  machinery, 
the  various  shops  and  buildings  are  of  brick  and  iron,  with 
cement  alleys,  not  a  particle  of  wood  being  used  in  their  con- 
struction. All  the  buildings  are  of  mill  construction,  thus 
lessening  their  liability  to  be  destroyed  by  fire,  and  saving  in 
insurance. 

Electric  motors  should  be  used  to  run  all  machines,  as  they 
save  fully  one-half  of  the  power  and  thus  increase  the  capacity 
of  the  plant,  as  power  is  developed  only  when  each  machine  is 
in  use.  They  require  no  line  shafts,  no  heavy  belts,  pulleys  or 
floor  space,  the  power  being  conveyed  by  wire  to  any  part  of 
the  beam-house,  tannery  or  currying  shop. 

Much  time  is  wasted  in  large  tanneries  by  men  running 
backward  and  forward  to  carry  messages.  Here  is  where  the 
telephone  is  now  used  in  leading  tanneries,  the  yards  and 
leach  house  and  other  parts  of  the  tannery  or  currying  shop 
being  all  connected  by  telephone. 


ELECTRIC  AND  OTHER  RAPID  TANNAGE  SYSTEMS.        53  I 


We  only  throw  out  these  suggestions  to  show  how  rapidly 
we  are  moving  forward,  and  there  can  be  no  stop  to  our  pro- 
gress. The  new  duty  of  15  %  on  hides  and  calfskins  may  hurt 
for  the  moment,  but  the  injury  will  not  be  permanent.  One 
thing  we  would  like  to  say  to  all  tanners  :  never  put  a  dirty 
hide  or  skin  into  any  kind  of  tanning  liquor;  clean  it  well  with 
a  mild  solution  of  borax,  pounds  to  the  IOO  gallons  of 
water.  It  will  pay,  and  then  you  will  be  on  the  road  to'quick 
tannage,  as  you  can  then  use  stronger  liquors  from  the  start. 


CHAPTER  XL. 


BLEACHING  LEATHER;   BLUING  WHITE  LEATHER;  BLEACHING 
SKINS  WITH  THE  HAIR  ON. 

BLEACHING  LEATHER. 

Chamois  leather  generally  possesses  a  quite  pronounced 
yellow  color  and  in  this  state  cannot  be  dyed  delicate  shades. 
But  even  the  best  quality  of  kid  prepared  by  the  process  of 
tawing  does  not  show  the  pure  white  color  required  for  the 
production  of  the  most  delicate  shades  of  pigeon  gray,  straw 
color,  etc.,  and  hence,  in  order  to  obtain  the  leather  absolutely 
white,  it  will  frequently  be  necessary  to  subject  it,  previous  to 
dyeing,  to  a  bleaching  process. 

Bleaching  is  mostly  effected  with  sulphurous  acid  either  in 
the  form  of  gas,  or  as  a  solution  of  it  in  water.  Sulphurous 
acid  is  the  product  of  the  combustion  of  sulphur  in  the  air 
and  is  the  cause  of  the  suffocating  odor  evolved  thereby. 

Formerly  leather  was  bleached  by  suspending  it,  in  a  wet 
state,  in  a  chamber  in  which  were  placed  vessels  containing 
sulphur.  The  chamber  was  hermetically  closed  and  kept  so 
for  twenty-four  hours.  The  gaseous  sulphurous  acid  ascend- 
ing from  the  burning  sulphur  dissolved  in  the  water  with  which 
the  leather  was  saturated  and  effected  the  bleaching  of  the  latter. 

This  process,  though  very  simple,  has  the  disadvantage  of 
the  bleaching  not  turning  out  uniform,  and  it  is  therefore  to  be 
preferred  to  effect  bleaching  by  means  of  a  special  apparatus, 
or  what  is  still  better,  to  use  a  solution  of  sulphurous  acid  in 
water.  For  the  former  purpose  various  apparatuses  have  been 
constructed,  the  general  arrangement  of  which  will  be  under- 
stood from  the  following  description  and  accompanying  illus 
tration  : 

(  532  ) 


BLEACHING  LEATHER. 


533 


The  bleaching  chamber  (Fig.  130)  consists  of  a  small  apart- 
ment papered  with  stout  paper  and  provided  with  a  window 
opening  outward,  and  which  can  be  hermetically  closed.  In 
the  ceiling  of  the  apartment  is  an  aperture  0  which  can  be 
closed  by  a  slide  and  communicates  with  a  chimney  E. 
Immediately  below  the  ceiling,  in  another  part  of  the  apart- 
ment, is  fixed  a  pipe  R  which  can  be  closed  by  a  stopper. 
Alongside  of  this  apartment  is  a  brick  chamber  K  provided 
with  a  hermetically  closing  door  T,  and  inside  with  roofing 
tiles  arranged  in  the  manner  shown  in  the  illustration.  This 


chamber  communicates  with  the  apartment  by  an  aperture 
above  the  floor  of  the  latter. 

The  leather  to  be  bleached  in  this  apparatus  is  suspended  in 
a  wet  state  upon  poles,  so  that  the  separate  sides  are  spread 
out  flat  and  do  not  touch  one  another.  The  door  and  window 
are  then  hermetically  closed,  the  slide  at  0  is  opened,  and  the 
sulphur  in  the  clay  vessel  S,  which  stands  in  the  chamber 
K,  ignited.  The  sulphur-vapor  carried  along  with  the  sul- 
phurous acid  evolved  by  the  combustion  of  the  sulphur  is 
condensed  on  the  roofing  tiles  in  the  chamber  K,  and  the 
gas  thus  purified  enters  the  bleaching  apartment.  The  sulphur 
is  allowed  to  burn  until  a  burning  match  held  in  front  of  the 


Fig.  130. 


Rl 


534 


THE  MANUFACTURE  OF  LEATHER. 


pipe  R  is  extinguished.  This  pipe,  as  well  as  the  aperture 
O  and  the  door  T  is  then  closed,  whereby  the  burning 
sulphur  still  remaining  in  the  vessel  5  is  immediately  ex- 
tinguished. After  twelve  hours  the  aperture  0  as  well  as 
the  doors  and  windows  is  opened,  the  bleached  leather  is 
taken  out  and  several  times  washed  in  water  to  remove  the  last 
traces  of  sulphurous  acid. 

BLEACHING  WITH  SOLUTION  OF  SULPHUROUS  ACID. 

The  use  of  liquid  sulphurous  acid  is  far  more  suitable  than 
the  preceding  process  with  gaseous  sulphurous  acid,  the 
bleaching  turning  out  much  better  and  more  uniform.  Fig. 
131  shows  the  arrangement  of  the  apparatus  for  the  produc- 
tion of  the  acid  required. 

It  consists  of  a  brick  chamber  provided  with  roofing  tiles 
arranged  in  the  same  manner  as  shown  in  Fig.  130.  Into  this 
chamber  enters  a  pipe  B  which  is  connected  with  a  pair  of 


Fig.  131. 


bellows.  On  the  other  side  of  the  combustion  chamber  the 
pipe  passes  into  a  forked  lead  pipe  RR  which  is  fixed  about 
two  inches  above  the  bottom  of  the  shallow  wooden  vat  W, 
and  on  the  lower  side  is  provided  with  numerous  narrow 
apertures. 

The  vat  W  is  filled  six,  or  at  the  utmost,  eight  inches  deep 
with  water  as  cold  as  possible,  and  the  pipe,  which  lies  in  the 
chamber  K,  is  also  covered  with  water.  The  sulphur  in  the 
vessel  5  is  then  ignited,  the  door  of  the  chamber  A'  (Fig.  131), 


BLEACHING  LEATHER. 


535 


which  is  provided  with  a  pane  of  glass,  closed,  and  the  bellows 
worked  slowly  but  uninterruptedly. 

The  sulphur  vapors  carried  along  by  the  sulphurous  acid 
evolved  by  the  combustion  of  the  sulphur  are  deposited  upon 
the  roofing  tiles  or  condensed  by  the  water  in  the  vat  W. 
The  gas  passes  out  through  the  narrow  apertures  of  the  pipe 
RR,  and  dissolves  abundantly  in  the  cold  water.  When  the 
water  has  a  strong  odor  of  sulphurous  acid  and  tastes  sour,  it 
is  sufficiently  impregnated  with  sulphurous  acid.  The  bellows 
are  then  stopped  and  the  cock  in  S  is  closed  to  prevent  water 
from  reaching  the  combustion  apparatus  in  consequence  of  the 
sucking  of  fluid  by  the  sulphurous  acid  contained  in  the  cool- 
ing pipe. 

For  bleaching  purposes  the  sulphurous  acid  thus  prepared 
is  brought  into  small  vats  of  suitable  depth,  and  the  wet  sides 
of  leather,  suspended  from  poles,  are  immersed  in  it,  so  that 
they  do  not  touch  one  another,  and  allowed  to  remain  about 
two  hours.  They  are  then  replaced  by  a  fresh  lot,  which  is 
allowed  to  remain  for  three  hours,  this  being  continued  until 
the  fluid  shows  but  a  very  slight  odor  of  sulphurous  acid. 
The  leather  when  taken  from  the  bleaching  fluid  is  immediately 
washed. 

BLEACHING  WITH  SODIUM  PEROXIDE. 

Dissolve  two  pounds  of  Epsom  salts  in  ten  quarts  of  water, 
and  add  gradually  to  the  solution  ten  ounces  of  sodium  dioxide. 
Apply  the  fluid  thus  obtained  to  the  leather  to  be  bleached. 
To  protect  the  leather  from  being  injuriously  affected  by  the 
bleaching  agent,  it  is  recommended  to  moisten  the  bleached 
portions  with  water  slightly  acidulated  with  acetic  acid. 

BLEACHING  WITH  HYDROGEN  PEROXIDE. 

Moisten  the  leather  to  be  bleached  with  water,  to  which  have 
been  added  a  few  drops  of  spirit  of  sal  ammoniac,  and  then 
apply  the  hydrogen  peroxide  with  a  rag  or  a  brush.  Repeat 
these  operations  alternately  until  the  leather  is  sufficiently 
bleached. 


536 


THE  MANUFACTURE  OF  LEATHER. 


BLEACHING  WITH  ALUMINIUM  HYPOCHLORITE  OR  MAGNESIUM  HYPOCHLORITE. 

These  bleaching  agents  are  formed  by  compounding  chlor- 
ide of  lime  solution  respectively  with  aluminium  sulphate 
solution  or  with  Epsom  salt  solution.  A  white  precipitate  of 
gypsum  is  formed,  which  in  a  short  time  deposits  completely. 
The  supernatant  clear  liquor  is  a  very  effective  bleaching  agent, 
and  has  the  additional  advantage  of  being  cheap.  It  is  applied 
to  the  leather,  and  after  a  few  minutes  wiped  off  by  means  of  a 
wet  rag  or  sponge. 

BLEACHING  CHAMOIS  LEATHER. 

Chamois  leather  cannot  be  bleached  with  sulphurous  acid 
alone,  and  agents  of  a  more  vigorously  oxidizing  action  have 
to  be  used  in  order  to  destroy  the  adhering  coloring  matter. 
For  this  purpose  potassium  permanganate  may  be  recom- 
mended. Dissolve  one  part  by  weight  of  potassium  perman- 
ganate in  twenty  parts  by  weight  of  water,  spread  the  leather 
upon  a  table,  apply  the  solution  and  rub  it  into  the  leather  with 
a  glass  ball.  During  this  manipulation  the  leather  becomes 
constantly  darker  and  finally  brown,  by  reason  of  the  potassium 
permanganate  becoming  decomposed  and  separating  manganic 
oxide,  which  is  of  a  brown  color. 

The  leather,  after  being  thoroughly  worked  with  the  glass 
ball,  is  rinsed  and  immersed  in  solution  of  sulphurous  acid  in 
water.  The  manganic  oxide  dissolves  with  ease,  and  the 
leather,  after  having  been  several  times  washed  and  finally 
dried,  appears  perfectly  white. 

BLUING  WHITE  LEATHER. 

Kid  leather,  not  pure  white,  can  be  made  so  by  bluing. 
However,  the  operation  has  to  be  executed  with  great  care, 
so  as  not  to  spoil  the  leather.  Dissolve  in  one  hundred 
quarts  of  water  about  three  drachms  of  water-soluble  aniline 
blue.  Wash  a  skin  in  the  solution  and  dry  it.  If,  after  dry- 
ing, the  color  is  of  a  too  yellow  cast,  add  gradually  very 
small  quantities  of  the  dye  stuff  until  the  desired  tone  is  ob- 


BLEACHING  LEATHER. 


537 


tained.  If,  on  the  other  hand,  the  leather  is  too  blue,  which 
is  more  frequently  the  case,  add  ten  quarts  of  water  to  the  bath 
and  repeat  this  until  the  desired  tone  is  obtained. 

By  this  simple  treatment  leather  of  a  quite  yellow  shade  may 
be  obtained  pure  white,  and  water-blue  leather  may  also  be 
prepared  ;  in  brief,  the  entire  scale  of  colors  between  yellowish 
white  and  bluish  white.  It  is,  however,  of  importance  always 
to  ascertain  the  strength  of  the  bath  by  an  experiment  with  a 
single  skin  in  order  not  to  obtain  leather  too  much  blued. 

BLEACHING  HEAVY  LEA!  HER. 

The  recipe  here  given  is  for  bleaching  bull's,  stag's  or  russet 
harness  leather : 

(i)  For  25  sides,  put  six  pounds  of  borax  in  five  pails  of 
water,  so  that  the  leather  is  entirely  covered.  Mill  for  15  min- 
utes. (2)  Dip  each  side  in  a  strong  solution  of  sulphuric  acid 
(30  degrees),  and  immediately  rinse  each  side  in  a  vat  of  clear 
water.  (3)  Return  the  sides  to  the  mill  and  put  in  2^  or  say 
3  pails  of  hot  strong  sumac.  Pour  in  one  quart  of  muriate  of 
tin.  Mill  for  15  minutes.  Take  out.  Slick  off  on  grain  side. 
Oil  evenly  over  and  hang  up  to  sammy,  suitable  for  setting. 
In  setting,  blend  water  with  stuffing  and  stuff  lightly  over,  just 
enough  to  lay  the  flesh  smooth.  The  most  important  point  is 
to  remember  to  get  the  tannin  out  of  the  liquor  before  starting 
in  the  acids,  by  giving  brisk  scouring.  For  a  table  set  for  this 
bleached  leather,  cook  one  pound  of  starch  in  two  gallons  of 
water  and  one  quart  cod  oil.  If  this  mixture  comes  out  a  trifle 
heavy  reduce  with  water.  It  will  leave  a  nice  white  flesh  on 
leather  free  from  heavy  greases.  Care  must  be  taken  that  none 
of  this  stuff  gets  on  the  grain  side.  Bleached  leather  ought  to 
be  dried  in  at  least  36  hours  ;  the  sooner  the  better,  in  order  to 
get  a  nice  uniform  color.  In  bleaching  light  sides,  say  four  to 
6  ounce  stock,  put  50  hides  into  the  mill. 

The  following  recipe  for  bleaching  leather  appeared  recently 
in  the  Riccttario  del  Conbiatoria  :  "  An  interesting  product,  re- 
cently introduced  for  the  bleaching  of  silk  and  wool,  has  been 


53« 


THE  MANUFACTURE  OF  LEATHER. 


successfully  employed  for  the  bleaching  of  leather.  This  agent 
is  the  dioxide  of  sodium.  Sold  in  tin  boxes,  and  having  the 
appearance  of  powder,  it  must  be  kept  far  from  wet  and  damp- 
ness, as  it  is  liable  to  decompose  quickly.  When  it  is  required 
for  bleaching  leather,  the  following  is  the  process  to  be  ob- 
served :  Dissolve  by  heat  two  pounds  of  sulphate  of  magnesia 
in  nine  quarts  of  water,  and  when  the  solution  gets  cold,  grad- 
ually add  eleven  ounces  of  dioxide  of  sodium.  The  leather 
required  to  be  bleached  is  rubbed  over  with  this  solution  until 
the  desired  white  or  clear  color  is  obtained.  If  the  leather  to 
be  treated  is  stout  and  heavy,  the  action  of  the  solution  may 
be  assisted  by  first  washing  the  leather  with  water  slightly 
acidulated  with  acetic  acid." 

IMPARTING  A  LIGHT  COLOR  TO  LEATHER. 

Although  the  tanner  will  always  strive  to  produce  as  light 
colored  a  leather  as  possible,  since  it  commands  a  higher  price, 
still  circumstances  may  occur  whereby  it  is  essentially  dark- 
ened. To  correct  this  he  will  try  to  give  it  a  light  shade  by 
artificial  means,  which  however,  if  performed  in  an  incorrect 
or  careless  manner,  most  generally  enhances  the  outward  ap- 
pearance of  the  leather  at  the  cost  of  its  interior  quality.  The 
toning  down  of  dark  leather  will  to  a  great  extent  remain  a 
knack  of  the  expert  tanner,  as  long,  at  least,  as  there  is  a  provo- 
cative cause;  in  other  words,  bad  tanning  material  on  the  one 
hand,  and  on  the  other  as  long  as  light  colored  leather  is  higher 
in  price  than  dark,  which  is  in  other  respects  just  as  good. 
Since,  however,  the  procedure  of  artificially  toning  down  the 
color  of  the  leather  is  fairly  difficult,  it  may  be  well  to  enter 
into  a  few  details  how  it  is  to  be  done,  so  as  to  cause  the  least 
injury  to  its  intrinsic  quality. 

A  difference  must  at  first  be  made  between  the  simple  ton- 
ing down  and  the  direct  bleaching.  While  in  the  latter  pro- 
cedure the  actual  color  of  the  leather  is  to  disappear  as  nearly  as 
possible,  to  be  replaced  by  a  more  or  less  pure  white,  the  aim 
of  the  former  is  to  simply  modify  the  dark  hue  and  cause  it  to 


BLEACHING  LEATHER. 


539 


become  paler;  but  it  is  not  the  purpose  of  the  process  to  make 
the  color  disappear  altogether,  which  has  been  recognized  to 
be  injurious,  and  perhaps  requires  the  raising  of  the  color 
again  by  artificial  means.  For  this  reason  actual  bleaching 
agents  cannot  be  used  for  the  simple  toning  down,  or  if  em- 
ployed, they  are  to  be  applied  with  the  greatest  care,  so  as  not 
to  produce  a  leather  white  outside  but  dark  within.  The 
agents  used  for  toning  down  are,  as  is  well  known,  highly 
diluted  acids,  in  which  the  leather  is  for  a  time  steeped.  Best 
liked  because  simplest  in  its  application  is  highly  diluted  sul- 
phuric acid,  or  else  acetic  acid,  while  with  lactic  acid  mixed 
with  bran,  there  is  danger  that  the  surface  of  the  leather  be 
corroded.  While  it  is  undeniable  that  the  toning  of  the  color 
with  these  acids  is  injurious  to  the  quality  of  the  leather,  the 
injury  is  in  large  part  due  to  the  circumstance  that  the  process 
is  incorrectly  conducted.  The  principal  fault  lies  in  entering 
the  more  or  less  dry  leather  into  the  water  very  feebly  acidu- 
lated with  sulphuric  acid.  The  immediate  consequence  is  that 
the  fluid  penetrates  into  the  innermost  parts  of  the  leather,  in 
other  words,  saturates  it,  while  as  a  toning  agent  it  is  simply 
required  on  the  surface.  Of  course,  another  advantage  is 
gained  thereby,  to  wit,  the  leather  is  toned  not  only  on  its 
surface,  but  also  in  its  interior,  and  the  fact  that  it  has  been 
subjected  to  this  treatment  is  not  so  readily  detected.  But 
this  process  is  performed  at  the  expense  of  the  quality  of  the 
leather,  because  this  is  saturated  into  its  core  with  sulphuric 
acid  which,  though  in  a  highly  diluted  state,  is  not  very  easy 
to  be  gotten  out  again,  consequently  it  can  exert  its  damaging 
effects  at  leisure.  It  would  therefore  be  a  great  improvement 
to  immerse  the  leather  first  in  clean  soft  water,  with  which  it 
would  become  saturated,  before  being  entered  into  the  sul- 
phuric acid  water.  If  the  leather,  already  saturated  with  clean 
water,  is  entered  into  the  acidulated  water,  little  or  else  nothing 
of  it  enters  into  the  interior,  where  it  is  really  not  wanted,  and 
where  it  can  simply  become  injurious,  but  it  remains  almost 
altogether  on  the  surface,  where  it  is  wanted  for  toning  the 


54Q 


THE  MANUFACTURE  OF  LEATHER. 


color.  The  importance  of  this  modification  will  at  once  be 
apparent  to  every  tanner,  and  it  would  also  be  of  interest  to 
the  leather  trade,  because  the  interior  quality  of  the  leather 
would  not  suffer  by  applying  the  acidulated  water  on  the  sur- 
face. But  here  again  the  objection  might  be  urged  that  the 
corrected  color,  in  consequence  of  the  non-penetration  of  the 
acid,  modifies  simply  the  surface,  and  the  leather  thus  cor- 
rected can  be  readily  distinguished. 

TO  BLEACH  SKINS  WITH  THE  HAIR  ON. 

The  following  methods  may  be  employed  with  advantage 
for  bleaching  lamb  or  goat  skins  intended  for  rugs,  lap- 
robes,  etc. :  A  quick  bleach  is  obtained  by  the  use  of  liquid 
sulphurous  acid,  the  skins  having  first  been  thoroughly  freed 
from  grease  by  washing  in  lukewarm  soapsuds  at  a  tempera- 
ture of  about  820  F.  Even  more  rapid  and  better  results, 
especially  in  the  bleaching  of  goatskins,  are  arrived  at  with 
Labarraque's  solution  (hypochlorite  of  soda)  ;  provided  suffi- 
cient care  is  exercised  to  have  the  bleaching  liquid  just  strong 
enough  in  chloride  of  sodium  and  the  skins  perfectly  clean,  a 
snow-white  bleach  can  be  obtained  inside  of  two  days  by  this 
method.  The  manner  of  preparing  Labarraque's  solution  is 
as  follows:  Mix  together  4^  pounds  chloride  of  lime  and  21 
quarts  water,  stirring  frequently  for  some  time.  Leave  the 
mixture  standing  until  thoroughly  settled,  and  then  strain  off 
the  perfectly  clear  portion  into  a  solution  of  lO}4  quarts  water 
in  which  have  been  dissolved  5  y2  pounds  Glauber  salts.  An  in- 
soluble precipitation  of  gypsum  results,  leaving  the  hypochlor- 
ite of  soda  in  solution.  The  clear  liquid,  which  should  be  quite 
free  from  lime,  is  next  drawn  off,  and  the  skins  immersed 
therein  until  thoroughly  bleached,  which  takes  about  two  days. 
After  removing  the  skins  from  the  bleaching  liquor,  rinse  well 
and  wash  in  weak  soapsuds  prepared  of  white  oil-soap,  in  order 
to  impart  the  necessary  soft  feel. 

Small  lambskins  can  be  treated  satisfactorily  by  the  method 
employed  for  bleaching  hog  bristles,  namely,  with  permangan- 


BLEACHING  LEATHER. 


541 


ate  of  potash  and  bisulphite  of  soda.  The  previously  cleansed 
skins  are  first  immersed  and  worked  for  three-quarters  of  an 
hour  in  a  bath  prepared  in  the  proportion  of  iTV  pounds 
crude  permanganate  of  potash  to  130  gallons  of  water,  heated 
to  950  F.  At  the  expiration  of  the  time  mentioned  they 
are  removed  and  placed,  without  rinsing,  in  a  second  bath 
of  130  gallons  of  water  to  7^  quarts  bisulphide  of  350  Be,  and 
pounds  hydrochloric  acid  of  20°  Be,  at  a  temperature  of 
1040  F.,  in  which  they  are  worked  until  perfectly  bleached. 

As  the  question  of  cost  of  material  and  the  actual  expense  of 
the  bleaching  process  is  of  secondary  importance  only,  the  use 
of  peroxide  of  hydrogen  or  peroxide  of  sodium  is  to  be  recom- 
mended. Experiments  have  proved  that  thoroughly  clean 
lambskins  can  be  bleached  beautiful  white  in  a  few  hours  with 
the  first-named  chemical.  The  peroxide  of  hydrogen  is  diluted 
in  8  to  10  times  its  own  weight  of  water,  to  which  is  added  a 
little  aqua  ammonia,  and  the  skins  immersed  until  the  desired 
result  is  attained. 


CHAPTER  XLI. 


LACE  LEATHER. 

Lace  leathers  are  either  tanned,  tawed,  or  made  from  raw 
hides,  and  both  these  varieties  as  well  as  picker  leathers,  which 
are  used  for  looms,  and  also  for  hamestrings,  are  generally  pro- 
duced in  the  same  tannery.  But  the  variety  of  lace  leather 
which  we  shall  describe  in  this  chapter  is  the  lighter  kind, 
which  is  manufactured  usually  from  Calcutta  hides,  the  heavier 
variety  being  made  from  light  cow-hides. 

When  the  dry  Calcutta  hides  are  used  they  are  first  placed 
to  soak  in  a  vat  of  water,  and  the  time  which  they  remain  is 
dependent  upon  the  weather,  one  or  two  nights  in  warm 
weather  and  three  or  four  nights  in  cold  weather  being  the 
usual  time.  The  water  used  for  the  soaks  should  be  softened 
with  borax,  as  has  been  previously  described. 

They  are  next  softened  in  the  hide-mill,  the  time  which  they 
are  worked  depending  upon  the  manner  in  which  the  hides 
have  been  cured. 

In  order  to  cleanse  them  from  dirt  the  hides  are  next  placed 
in  the  wash-mill  and  worked  for  fifteen  or  twenty  minutes  with 
water  softened  with  borax,  which  operation  also  removes  the 
wrinkles. 

Upon  being  removed  from  the  wash-mill,  the  hides  are 
spread  flat  upon  the  floor  and  slit  down  the  back  and  thus 
divided  into  sides. 

They  are  then  placed  upon  trucks  and  carried  to  the  lime- 
vats,  where  they  are  spread  flat  upon  the  floor  alongside  the 
vats  and  whitewashed,  by  passing  over  them  a  swab  which  has 
been  dipped  in  a  solution  of  lime. 

This  coat  of  whitewash  is  applied  to  the  hair  side,  and  the 

(  542  ) 


LACE  LEATHER. 


543 


sides  are  piled  two  hundred  high,  and  in  warm  weather  this 
pack  remains  over  night,  but  in  winter  the  sides  are  placed  in 
the  lime-vats  the  same  day,  in  order  to  prevent  the  whitewash 
from  chilling.  In  warm  weather  the  sides  remain  in  the  limes 
about  ten  days,  but  in  cold  weather  the  period  is  longer. 

It  is  best  to  mix  sodium  sulphide  with  the  lime,  as  the  un- 
hairing  is  done  more  quickly  and  the  gelatine  of  the  hide  is 
sound. 

When  the  hair  is  loosened,  the  sides  are  removed  from  the 
vats  with  tongs  and  immediately  unhaired,  after  which  they  are 
placed  in  water  in  a  vat  having  a  revolving  paddle  wheel  and 
washed,  the  England  wheel  and  vat  being  the  one  commonly 
employed,  and  upon  removal  are  worked  on  the  beam  to  remove 
the  lime. 

They  are  then  fleshed  and  bated  in  C.  T.  bate  (manufactured 
by  Martin  Dennis  Chrome  Tannage  Co.,  Newark,  N.  J.). 

As  a  further  preventive  against  lime  the  sides  are  placed  in 
a  large  revolving  wheel,  called  a  "  tub  wheel,"  in  which  they 
are  washed  for  about  three-quarters  of  an  hour,  and  upon  re- 
moval from  this  wheel  the  sides  are  placed  in  the  tanning 
liquors  and  remain  until  tanned.  When  this  has  been  accom- 
plished the  sides  are  exposed  to  the  air  to  dry  and  next 
stretched,  a  machine  for  which  purpose  is  shown  in  Figs.  132 
to  134;  but  the  stretching  is  also  performed  by  hand  on  the 
stretch-  bench. 

As  is  well  known,  all  hides  vary  considerably  in  thickness  at 
different  points,  and  when  taken  from  the  liquor-vats  they  are 
found  to  be  soft,  flabby,  wrinkled  and  fulled.  Owing,  there- 
fore, to  this  condition  of  the  hides,  it  is  necessary,  before  they 
are  dressed  and  finished  for  the  market,  that  they  be  stretched 
throughout  to  remove  the  wrinkles  and  fulness,  and  also  to  re- 
duce those  parts  which  are  thicker  than  other  portions,  so  that, 
as  far  as  possible,  the  hides  shall  be  uniform  in  thickness. 

Mechanical  devices  are  capable  of  producing,  in  connection 
with  hand  manipulation,  the  desirable  results  of  thoroughly 
stretching  the  hides,  and  rendering  them  of  even  thickness  in 


544 


THE  MANUFACTURE  OF  LEATHER. 


all  parts.  These  devices  usually  comprise,  in  the  main,  a  fric- 
tion table  or  beam,  over  which  the  hides  are  dragged,  a  stretcher- 
bar  of  suitable  form  for  stretching  the  hides  transversely,  and  a 
slowly-revolving  roller,  to  which  the  edge  of  each  hide  is 
secured,  and  around  which  it  is  wound  after  being  drawn  over 
the  table  or  beam  and  the  stretcher- bar.  After  the  sides  have 
been  well  worked  on  the  stretch-bench  they  are  split  evenly  by 
the  splitting  machine. 

The  sides  are  next  stuffed  with  tallow  and  neat's-foot  oil,  the 
proportions  of  which  change  somewhat  according  to  the  tem- 
perature and  season,  less  oil  and  more  tallow  being  used  in 
summer  than  in  winter. 

If  the  tannage  is  alum  or  vitriol,  stuff  in  a  wheel  with  the 
stuffing  900  F.  Curriers  stuff  leather  when  moist,  but  figure 
the  material  to  every  100  pounds  of  dry  leather.  They 
get  this  weight  by  deducting  one-third  from  the  weight  of  the 
sammied  leather  to  be  stuffed.  Therefore  (reckoning  on  this 
basis),  to  100  pounds  of  dry  lace  leather  use  10  pounds  tallow, 
10  pounds  degras  and  10  pounds'  cod  oil,  melted  together 
and  put  in  wheel  at  900  F.  Time  of  wheeling  depends  on 
tannage  and  speed  of  drum.  It  requires  some  time  to  get 
grease  into  alum  leather.  The  wheel  might  have  to  be  run  one 
hour.  In  a  larger  wheel  shorter  time  is  necessary  than  in  a 
smaller  wheel.  In  an  eight  or  ten  foot  drum  three-quarters  of 
an  hour  wheeling  ought  to  suffice,  and  would  keep  the  leather 
of  a  nice  color.  Grease  tends  to  make  tough  leather.  The 
heavier  the  grease  the  tougher  the  leather.  If  more  oil  is  used, 
leather  becomes  soft  and  rather  short- fibred.  If  it  were  possi- 
ble to  stuff  entirely  by  tallow  the  leather  would  be  very  tough. 

The  sides  are  then  hung  upon  sticks  in  tiers  in  the  drying- 
room,  which  is  commonly  heated  by  exhaust  steam  from  the 
engine. 

After  being  removed  from  the  drying-room  the  sides  are 
softened,  the  machine  shown  in  Figs.  135  to  143  being  now 
usually  employed  for  this  purpose  in  place  of  the  old-fashioned 
pin-block. 


LACE  LEATHER. 


545 


The  sides  are  next  rolled  out  smoothly  on  a  glassing  machine, 
and  then  shaved  on  the  flesh  side  and  buffed  with  a  currier's 
knife,  in  which  latter  operation  the  grain  is  removed  in  order  to 
prevent  the  lacing  from  cracking;  about  seventy-five  sides 
being  a  fair  day's  work  for  one  man.  They  are  next  rubbed 
with  a  mixture  of  lard  oil,  tallow,  and  flour,  and  the  sides  of 
lace-leather  are  then  finished  by  laying  them  upon  a  flat  table 
and  smoothing  them  out  with  a  glass  slicker. 

To  obtain  the  golden  yellow  color  so  much  desired  in  lace 
leather,  an  old  experienced  tanner  recommends  the  addition  of 
pulverized  brimstone  or  sulphur  to  the  tanning  liquor.  The 
sulphur  acts  as  a  tanning  agent  as  well  as  a  colorant.  About 
2  oz.  is  the  quantity  of  sulphur  requisite  to  a  side.  For  a 
darker  shade,  take  2  oz.  japonica  instead  of  sulphur,  using  it 
in  same  manner. 

junior's  methods  of  manufacturing  lace-leather. 

The  following  process  for  manufacturing  lace-leather  is  used 
by  Junior,  of  Belleville,  111.  There  is  no  patent  on  the  process, 
but  Mr.  Junior  claims  one  on  the  tanning  compound,  which 
patent  has  now  expired. 

The  hides  in  this  method  go  through  the  following  pro- 
cesses :  — 

First.  Soak  the  hides  in  fresh  water  for  twenty-four  hours. 

Second.  Soak  the  hides  in  freshly  slaked  lime-water  as  long 
as  necessary  to  make  the  hair  removable  by  scraping. 

Third.  Put  the  unhaired  hides  into  fresh  lime-water  once 
more  for  two  days. 

Fourth.  Scrape  off  all  fleshy  parts  on  the  inside;  then  soak 
the  hides  in  fresh  water  to  free  them  from  all  lime. 

Fifth.  Then  rub  the  hides  with  a  "  slick-stone,"  in  order  to 
smooth  or  burnish  them  and  to  squeeze  out  all  impurities. 

Sixth.  Soak  the  hides  for  about  twelve  hours  in  warm  water, 
containing  one  pound  of  wheat  bran  and  one-half  pound  of  a 
ferment  to  every  five  gallons  of  water,  until  the  hides  cease  to 
swell,  and  all  lime  is  neutralized. 
35 


546 


THE  MANUFACTURE  OF  LEATHER. 


Seventh.  Then  squeeze  them  well  with  the  scrape-iron. 

Eighth.  Immerse  the  hides  in  the  composition  given  below, 
in  which  they  remain  for  from  twelve  to  twenty-four  hours  until 
they  are  well  saturated. 

This  composition  consists  of  the  following  ingredients  com- 
bined in  proportions  stated :  For  every  ten  pounds  of  hide — 
pure  water,  five  gallons;  alum,  one  pound;  sal-soda,  four 
ounces;  common  salt,  four  ounces  ;  wheat  bran  (or  other  bran), 
four  ounces.  Of  these  ingredients  the  crystalline  salts  should 
be  thoroughly  dissolved  and  mingled  by  agitation  with  the  bran. 
It  is  claimed  that  the  application  in  tanning  of  this  solution,  in 
connection  with  the  other  treatment  of  the  hides,  has  the  effect 
of  preserving  the  whole  natural  strength  of  the  same,  which  is 
possible  only  in  the  absence  of  free  acids.  After  the  hides 
have  become  saturated,  they  are  removed  from  the  solution  and 
hung  up  to  dry. 

Ninth.  Now  work  them  well  on  the  stretch-bench  and  split 
them  evenly  on  the  splitting-machine. 

Tenth.  Rub  into  the  hides  a  mixture  of  about  three  pounds 
of  lard  oil  and  one  pound  of  tallow,  and  let  dry  well. 

Eleventh.  Soak  in  rain-water  containing  bran,  and  in  this 
wet  state  stretch  the  hides  well  on  the  stretch-bench. 

Twelfth.  Now  shave  them  as  clean  as  possible  on  the  flesh 
side,  and  especially  carefully  on  the  grain  side,  in  order  to  re- 
move the  whole  grain,  which  removal  produces  the  elasticity 
which  prevents  the  liability  to  cracking. 

Thirteenth.  Then  finally,  rub  into  the  hides  a  mixture  of  one 
and  one-half  pounds  of  lard  oil,  one-half  pound  of  tallow,  and 
one-eighth  pounds  of  fine  flour  for  every  ten  pounds  of  hide 
(which  process  helps  to  produce  smoothness  and  durability  of 
the  leather),  let  them  dry,  then  stretch  and  smooth  them  well 
with  a  wooden  stretcher,  and  now  the  hides  are  ready  for  use. 

QUICK  TANNING  PROCESS  FOR  LACE  AND  WHIP  LEATHER. 

The  method  patented  in  1875  by  Bartenbach  and  Richter,  of 
Detroit,  Mich.,  is  as  follows: 


LACE  LEATHER. 


547 


For  making  lace  and  whip  leather  the  hides  are  cleaned  after 
soaking,  the  hair  being  removed.  Then  put  them  in  the  follow- 
ing solution,  enough  being  used  to  fairly  submerge  them  :  To 
twenty-five  gallons  of  warm  water  add  two  pounds  of  alum, 
fifteen  pounds  of  salt,  one  pound  of  sulphuric  acid,  two  pounds 
of  wheat  bran,  two  ounces  of  dissolved  sulphur.  The  hides  are 
left  in  this  solution  for  twenty  to  twenty-five  minutes,  after 
which  one  ounce  of  vitriol,  four  pounds  of  salt,  and  two  ounces 
of  alum,  dissolved  in  one-half  gallon  of  water,  are  mixed  with 
the  solution,  and  the  hides  are  left  to  remain  in  it  twenty 
minutes  longer.  The  hides  are  then  taken  out  and  well  wrung, 
and  hung  up  to  dry  in  a  dark,  airy  place.  Those  intended  for 
whip  leather,  when  dry,  are  moistened  with  a  little  water,  and 
stretched  upon  a  stretching-iron.  Those  intended  for  lacing- 
leather,  after  being  well  dried,  are  rubbed  with  a  mixture  of  one 
pound  of  fish  oil,  one  pound  of  tallow,  four  ounces  of  linseed 
oil,  and  two  ounces  of  soap-soda  in  a  gallon  of  hot  water. 

loescher's  method  for  manufacturing  lace  leather. 

In  1876  H.  Loescher,  of  Chicago,  111.,  patented  the  following 
method  for  manufacturing  lace  leather,  the  object  claimed  being 
to  produce  lace  leather  of  greater  strength  and  tenacity  than 
that  produced  by  treating  skins  with  lime  and  acids. 

The  first  step  in  this  process  is  to  remove  the  hair  from  the 
hide  by  fermentation  by  subjecting  it  to  a  decaying  process  for 
a  few  days.  The  next  step  is  to  dry  the  skin  to  a  flinty  hard- 
ness ;  and  the  last  step  consists  in  subjecting  the  dried  skin  to  a 
process  of  torsion  and  beating  until  thoroughly  softened,  when, 
it  is  claimed  that  it  will  have  the  toughness  of  rawhide,  with 
the  pliability  of  kid. 

coupe's  stretching  machine. 

The  machine  for  stretching  leather  shown  in  Figs.  132  to  134 
is  the  invention  of  Wm.  Coupe,  of  Attleborough,  Mass.,  who  is 
an  extensive  manufacturer  of  lace  leather. 

Figure  132  represents  a  front  elevation  of  Coupe's  machine. 


548 


THE  MANUFACTURE  OF  LEATHER. 


Fig-  !33  shows  the  same  in  central  vertical  transverse  section, 
and  Fig.  134  represents  the  stretcher-bar  in  perspective. 

As  particularly  shown  in  Fig.  132,  the  machine  consists  of  the 
following  devices:  A  pair  of  standards  as  at  A  A',  in  which  is 
mounted  a  shaft,  as  at  B,  to  which  power  is  applied.    Upon  one 


Fig.  132.  Fig  133. 


end  on  this  shaft  is  a  pinion,  as  at  C,  arranged  to  mesh  with  a 
gear,  as  at  D,  loosely  mounted  on  one  end  of  a  roller,  as  at  E. 

The  inner  side  of  this  gear,  D,  is  provided  with  a  clutch  face 
or  pin  as  at  d,  for  engagement  with  a  clutch  as  at  F,  splined  to 
the  roller  E,  and  furnished  with  a  slipping-handle  as  at  G,  so 
arranged  as  to  be  convenient  of  access  to  the  operating 
attendant.  The  remaining  parts  of  the  machine  consist  of  a 
narrow  table  or  breast-beam  as  at  H,  which  is  mounted  in 
mortises  as  at  a,  in  the  standards  A  A',  and  a  stretcher-bar  as 


LACE  LEATHER. 


549 


at  A',  likewise  mounted-in  mortises  as  at  a',  and  having  its  two 
working  faces  doubly  inclined  as  at  k,  k',  Fig.  134. 

The  operation  of  the  machine  is  as  follows: 

A  hide  is  placed  over  the  table  or  breast-beam,  H,  and  one 
of  its  ends  carried  under  the  stretcher-bar,  A',  and  secured  to 
the  roller,  E,  by  the  clamp,  e,  the  other  end  hanging  free  in 
front  of  the  machine,  as  shown  in  Fig.  133.  The  operator  now 
connects  the  roller,  E,  to  the  continuously-revolving  gear,  D, 
by  means  of  the  handle,  G,  and  clutch  F,  and  the  roller,  E, 
slowly  revolves,  winding  the  hide  around  its  surface,  and  draw- 
ing it  over  the  friction  table  or  beam,  H,  and  around  the 
stretching-bar,  K. 

When  any  part  of  the  hide,  the  thickness  of  which  is  to  be  re- 
duced, or  the  wrinkled  or  fulled-up  portion  smoothed  out,  passes 
over  the  table  or  beam,  H,  the  operator  who  stands  in  front  of 
the  beam  applies  pressure  by  hand  to  the  proper  portions, 
thereby  increasing  the  friction  between  the  under  surface  of  the 
hide  and  the  surface  of  the  bar,  H,  and  causing  the  onward 
movement  of  such  portions  to  be  retarded.  The  portions  thus 
pressed  upon  are  more  severely  stretched  than  other  parts  of 
the  hide,  and  by  proper  manipulation  by  the  attendant  its  thick- 
ness is  rendered  uniform,  and  it  passes  to  the  stretching-bar,  K, 
in  a  smooth  condition,  having  been  longitudinally  stretched 
upon  the  beam,  H. 

In  passing  over  the  bar,  A',  the  hide  is  transversely  stretched 
by  the  doubly-inclined  sides,  k,  k',  from  which  it  passes  onward 
to  the  roller,  E,  winding  about  the  roller  uniformly  and  smoothly. 
The  machine  is  now  stopped,  the  hide  removed,  another  secured 
to  the  roller,  E,  and  the  operations  above  described  are  repeated. 

HDD's  SOFTENING  MACHINE. 

Figs.  135  to  143  show  the  machine  invented  by  J.  Tidd,  of 
Woburn,  Mass.,  which  is  much  used  for  softening  lace  leather. 

Fig.  135  is  a  side,  and  Fig.  136  an  end  elevation.  Fig.  137 
shows  the  under  side  of  the  cross  head  G.  Fig.  138  is  a  top 
view  of  the  bed  B.    Fig.  139  is  the  under  side  of  a  grooved 


550 


THE  MANUFACTURE  OF  LEATHER. 


cross-head.  Fig.  141  is  the  top  side  of  a  grooved  bed.  Fig. 
143  is  a  side  view  of  a  grooved  cross-head,  with  a  corrugated 
or  serpentine  rib  /,  instead  of  the  pins  C.  Figs.  140  and  142 
are  end  views  of  Figs.  139  and  141. 


Fig.  135. 


4 


1SL 


Jf 


2s-* : 


Fig.  136. 


Fig.  137. 


0^0000000 

0000000 


Fig.  138. 


o°o090o0o0o0o°o 


2) 


Fig.  139. 


Fig.  140. 
§3 


The  perforated  bed  B,  is  secured  to  the  top  of  a  supporting- 
beam  K,  in  combination  with  a  yielding  cross-head  G,  and  a 
series  of  pins  c,  projecting  downward  from  the  under  side. 
Each  perforation  a  in  the  bed  B  is  directly  under  a  correspond- 
ing pin  in  the  cross-head.  A  shaft,  H,  is  arranged  in  bearings  at 
or  near  the  centre,  and  near  the  bottom  of  the  framework,  and 
on  each  end  of  this  shaft  is  a  balance-wheel  /,  outside  of  the  legs 
b,  and  on  the  same  shaft  inside  of  and  near  one  leg  is  a  pulley 


LACE  LEATHER. 


551 


A,  to  receive  the  belt  which  drives  the  machine.  Projecting 
outward  from  each  of  the  wheels  /,  are  crank-pins  or  wrist-pins 
i,  and  the  lower  end  of  a  pitman,  k,  connects  with  each  pin  i. 
The  upper  end  of  each  pitman  connects  with  the  lower  end  of  a 
vertical  rod  m,  which  passes  freely  through  a  hole  in  the  beam 
K,  and  extends  upward  through  the  cross-head  G.  These  rods 
m  are  screw-threaded  from  their  upper  ends  downward  to  a 
little  below  the  cross-head  G,  and  the  latter  is  connected  with 
the  rods  m  by  nuts  d  beneath  the  cross-head,  and  by  similar 
nuts  e  above.    The  nuts  d  are  for  raising  or  lowering  the  cross- 


Fic;.  141.  Fig.  142. 


head  to  any  desired  point  of  adjustment,  and  the  nuts  e  are  to 
screw  down  or  up,  and  increase,  release,  or  diminish  the  action 
of  the  springs  g,  which  are  arranged  between  the  nuts  e  and 
the  upper  side  of  the  cross-head  G,  so  as  to  allow  the  latter  to 
yield  when  the  leather  is  placed  on  the  perforated  bed,  beneath 
the  cross-head  and  the  pins  c,  the  downward  motion  of  which 
brings  the  lower  ends  of  the  pins  into  contact  with  the  leather, 
pressing,  forcing,  or  bending  certain  portions  of  the  leather,  and 
in  succession  other  portions,  across  the  edges  of  the  perforation 
a,  thereby  limbering  and  softening  the  leather  to  the  desired 
degree,  or  in  proportion  to  the  time  the  leather  is  moved  about 
between  the  perforated  bed  and  the  pins  and  cross-head  while 
in  motion  or  action. 

Instead  of  perforated  bed  and  the  pins,  there  are  sometimes 
used  a  grooved  bed  and  a  grooved  cross-head,  shown  in  Figs. 
139,  140,  141  and  142,  and  either  straight  or  corrugated  or 


552 


THE  MANUFACTURE  OF  LEATHER. 


serpentine  horizontally,  as  in  Fig.  141,  but  the  perforated  bed 
and  the  pins  for  softening  most  kinds  of  leather  and  hides  are 
preferable,  as  they  require  less  power,  and  have  a  tendency  to 
enlarge  the  side  or  piece  of  leather  or  hide,  by  the  peculiar 
operation  of  the  pins  and  perforations  drawing  in  every  direc- 
tion ;  whereas,  in  all  previous  modes  of  softening  leather,  such 
as  pounding  the  leather  with  a  wooden  mallet  when  spread  out 
on  the  tops  of  several  pins  promiscuously  disposed,  the  leather 
was  considerably  contracted  or  reduced  in  size,  and  very  im- 
perfectly and  unequally  softened. 

This  machine  is  driven  by  a  belt  from  some  rotating  pulley 
on  to  the  pulley  A,  which  rotates  the  shaft  H  and  wheels  or 
cranks  /,  through  the  medium  of  which,  and  the  pitman  k  and 
rods  m,  the  cross-head  G  and  pins  c  are  moved  up  and  down 
about  two  hundred  strokes  per  minute.  The  leather  or  the 
hide  is  moved  or  fed  along  over  the  bed  B,  while  the  pins  c 
strike  or  press  portions  of  the  leather  into  the  perforations, 
changing  from  one  portion  to  another  until  the  whole  surface 
of  the  leather  has  been  acted  upon,  and  the  entire  side  or  piece 
of  leather  is  well  and  perfectly  softened. 


CHAPTER  XLII. 


THE  DYEING  OF  LEATHER. 

The  introduction  of  coal  tar  colors  has  given  an  almost  un- 
limited range  of  shades  and  tones  and  methods  of  producing 
them.  It  is  in  this  very  large  range  that  most  of  the  colorist's 
troubles  lie,  making  it  an  almost  insurmountable  difficulty  to 
produce  more  than  one  lot  of  a  uniform  color.  The  currier 
must  have  a  very  large  experience  with  the  "  crankisms"  of  the 
various  dyestuffs  and  the  conditions  which  govern  their  appli- 
cation in  order  to  produce  certain  colors,  and  it  is  here  that  a 
knowledge  of  chemistry  combined  with  keen  observation  and 
care  will  stand  him  in  good  stead.  The  following  hints  may  be 
of  value  to  him  in  his  efforts  to  obtain  a  uniformly  colored  lot: 
"The  resulting  color  produced  by  brushing  or  dipping  a  piece 
of  leather  in  a  solution  of  aniline  dye  depends  (a)  on  the 
strength  of  the  solution  ;  (/?)  the  time  of  duration  of  immersion 
or  number  of  times  the  solution  is  brushed  over  it;  (c)  the 
temperature  of  the  dye  bath;  (d)  the  nature  of  the  mordant 
used  before  applying  the  dye;  (e)  nature  of  the  "striker"  or 
"topping  agent"  applied  after  the  application  of  the  dye;  (f) 
the  tanning  process  to  which  the  leather  has  been  subjected, 
whether  hemlock,  union,  oak,  sumac  or  tawed  leather  is  being 
dyed  ;  (g)  the  temperature  at  which  dyed  leather  is  dressed,  etc. 

As  is  well  known,  the  so-called  aniline  colors,  partly  on  ac- 
count of  the  beauty  of  their  hues,  with  which  they  frequently 
unite  a  high  degree  of  fastness,  seem  to  be  specially  adapted 
for  the  purpose  of  leather  dyeing,  and  are,  almost  all  of  them, 
greedily  absorbed  by,  and  fixed  upon,  the  leather.  For  this 
reason  a  special  mordant  is  barely  ever  required  for  preparing 
the  leather  for  absorbing  a  color.    It  suffices  generally  to  apply 

(553  ) 


554 


THE  MANUFACTURE  OF  LEATHER. 


the  color  directly  upon  the  leather.  It  may  be  regarded  as  a 
general  rule  that  an  aqueous  solution  is  much  more  readily 
absorbed,  and  the  shades  obtained  are  much  clearer  and 
brighter  than  when  using  an  aniline  soluble  only  in  alcohol,  for 
the  very  simple  reason,  because  a  finer-grade  leather  with  deli- 
cate grain  cannot  well  stand  the  treatment  with  strong  alcoholic 
solutions.  If  a  dye  is  to  be  used  which  is  under  no  conditions 
soluble  in  water,  the  dyer  must  at  least  dilute  the  alcoholic 
solution  of  dyestuff  with  water  to  such  a  degree  that  the  latter 
will  just  remain  suspended  in  the  liquor.  It  is  self-evident,  of 
course,  that  the  process  of  dyeing  can  also  with  aniline  dyes 
be  performed  in  a  manner  similar  to  other  dyes — by  dipping 
into  the  fluid  as  well  as  by  painting  it  on;  but  in  a  few 
exceptional  cases,  it  is  better  to  effect  the  dyeing  by  painting 
on  the  color.  Considering  their  capacity  for  being  toned, 
the  aniline  dyes  can  be  applied  in  almost  all  light  shades 
of  color.  The  greater  part  of  the  yellow,  orange,  brown  and 
gray  dyestuffs  are  applied  by  painting,  though  fuchsine  and 
methyl  violet  are  also  applied  in  this  manner.  Should  the  one 
or  the  other  aniline  dye  not  take  uniformly  upon  the  leather,  a 
mordant  is  to  be  used.  Tanned  leather  which  is  rather  dark, 
is  best  bleached  first.  This  is  done  by  drawing  the  leather 
several  times  through  a  strong,  warm,  sumac  decoction,  or  else 
leaving  it  immersed  in  it  for  a  few  hours.  A  priming  with  pic- 
ric acid,  also  to  be  used  in  an  aqueous  solution,  is  to  be  recom- 
mended for  several  aniline  colors.  The  dyestuff  solutions  must 
be  prepared  carefully  in  a  suitable  state  of  dilution,  which  is 
readily  seen  by  testing  upon  a  piece  of  glass  or  white  paper. 

By  the  name  of  mordants  the  dyer  designates  a  class  of 
agents,  the  function  of  which  is  to  prepare  a  material  to  be 
subjected  to  dyeing  to  receive,  to  "fix"  the  dyestuff  upon  the 
latter.  According  to  their  action  upon  a  material,  the  gener- 
ally used  mordants  may  be  divided  into  three  groups,  to  wit: 
I,  acids;  2,  bases;  3,  salts.  The  bases  hold  a  secondary  place 
in  leather  dyeing.  The  most  important  are  :  Ammonia,  caustic 
potash,  and  caustic  lime.    The  important  salts  used  in  leather 


THE  DYEING  OF  LEATHER. 


555 


dyeing  are:  I,  sulphate  of  iron;  2,  sulphate  of  copper;  3, 
sulphate  of  zinc;  4,  sulphate  of  alumina;  5,  alum  (a  double 
combination  of  two  sulphates);  6,  nitrate  of  iron;  7,  nitrate 
of  lead;  8,  chloride  of  ammonium;  9,  chloride  of  iron;  10, 
chloride  of  tin  ;  1 1,  chlorate  of  tin;  12,  chloride  of  sodium; 
13,  acetate  of  iron;  14,  acetate  of  alumina;  15,  acetate  of 
lead;  16,  acetate  of  copper;  17,  tartar;  18,  carbonate  of  pot- 
ash; 19,  carbonate  of  soda;  20,  bichromate  of  potash;  21, 
chromate  of  lead  ;  22,  potassium  ferro-cyanide,  etc. 

The  most  impoatant  of  the  salts  are  the  different  soaps, 
formed  by  the  action  of  an  alkali  upon  a  fat  or  an  oil.  A  good 
hard  soda  soap  is  in  general  best  for  the  purpose  of  leather 
dyeing,  and  the  only  point  to  be  attended  to  is  that  it  be  white 
and  not  too  strongly  alkaline.  The  best  sort  is  one  prepared 
from  olive  oil,  known  in  commerce  as  castile  soap,  and  it  is 
generally  used  for  preparing  the  leather  to  absorb  the  dye- 
stuff.  Before  entering  upon  the  actual  process  of  coloring  the 
leather,  it  is  to  be  assorted  according  to  its  color,  and  destined 
to  be  dyed  of  a  hue  for  which  it  is  best  suited.  The  hand- 
somest skins  are  used  for  light  brown,  lemon  yellow,  orange, 
violet,  etc.  Inferior  ones  are  colored  dark  green,  iron  gray 
and  black.  It  is  best  to  prepare  the  colors  for  the  occasion, 
and  use  them  as  soon  as  cold.  Let  the  operator  remember  in 
this  connection,  that  if  he  wishes  to  produce  the  possibly  best 
effects,  he  must  observe  the  greatest  cleanliness  in  all  the  dif- 
ferent stages.  The  cloth  or  sieves  through  which  the  colors 
are  strained,  the  vessels  for  them,  the  brushes,  the  tables,  all 
must  be  kept  scrupulously  clean.  There  must  be  a  brush  for 
every  color. 

Dark  Brown. — Eight  parts  fustic,  I  part  logwood,  2  parts 
Brazil  wood,  I  part  sanders,  one-half  part  quercitron,  are 
placed  in  a  clean  copper  boiler,  soft  water  is  poured  in  so  that 
it  stands  about  two  inches  above  the  dyewood.  The  whole  is 
boiled  for  about  one  hour,  the  decoction  then  strained  through 
linen,  and  when  cold  used  for  dyeing.  When  the  skin  has 
been  painted,  it  is  rinsed  with  cold  water  while  upon  the  table, 


556 


THE  MANUFACTURE  OF  LEATHER. 


the  leather  well  stretched  with  a  brass  slicker,  another  coat  of 
the  dye  is  applied,  again  washed  off  with  cold  water,  and  the 
skin  is  rubbed  until  the  water  runs  off  clean.  Colors  that  re- 
quire to  be  darkened,  are  washed  with  a  solution  of  iron 
vitriol,  consisting  of  385  to  465  grains  Salzburg  vitriol  *  in 
three  quarts  of  water.  This  solution  is  brushed  evenly  over 
the  skin,  and  after  having  been  absorbed  somewhat,  the  latter 
is  again  washed  with  clean  water,  and  set  aside  to  dry. 

Light  Brown. — The  above-described  color  also  serves  for 
dyeing  light  brown,  with  this  difference  only,  that  a  dilute  pot 
ash  priming  is  given  and  the  vitriol  bath  dispensed  with. 

Olive  Brown. — Two  parts,  by  weight,  of  Hungarian  fustic,  1 
part  quercitron,  and  ]^  part  logwood  are  extracted  by  boiling, 
and  the  fluid  is  then  applied  upon  a  strong  potash  priming,  a 
vitriol  bath  being  subsequently  given. 

Cutch  Brown. — A  decoction  of  18  ozs.  of  cutch,  with  42 
quarts  of  water  and  2.1 1  ozs.  of  sulphate  of  copper,  is  applied 
upon  the  feebly-primed  skin. 

Chestnut  Brown. — The  moistened  leather  is  primed  with  a 
solution  of  2^  lbs.  of  acetate  of  copper  in  52  quarts  water.  It 
is  then  rubbed  with  the  slicker,  and  a  coating  of  yellow  prus- 
siate  of  potash  in  slightly-acidulated  water  is  applied. 

Chocolate  Brown. — One  and  one-half  parts  Brazil  wood  are 
boiled  in  45  parts  water  for  two  hours,  after  which  a  little  pyro- 
lignite  of  iron  is  added,  according  to  shade. 

Red. — A  fine  red  of  an  admirable  shade  is  produced  by  a 
coating  with  cochineal  color,  prepared  of  an  optional  strength 
by  boiling  cochineal  in  a  linen  bag  in  water,  to  which  about  2 
per  cent,  aqua  ammonia  has  been  added. 

Alizarine  Red  (a  feeble  flesh  color)  is  obtained  by  brushing 
over  the  leather  a  solution  of  alizarine  or  madder  extract  in 
dilute  soda  lye,  after  which  rinse  with  soap  water. 

Scarlet  is  produced  by  painting  with  Zaffer  extract,  espec- 
ially if  the  leather  was  previously  primed  with  a  feeble  annatto 


*  In  chemistry  called  ferroso-cupric  sulphate  (mixed  iron  and  copper  vitriol). 


THE  DYEING  OF  LEATHER. 


557 


bottom.  The  Zaffer  extract  is  diluted  with  water,  in  the  pro- 
portion of  about  I  part  extract,  60  parts  water,  i  part  tartar. 

Ordinary  Red. — An  ordinary  red  is  obtained  by  the  decoc- 
tion of  sanders  wood  upon  a  feeble  priming  of  alum  free  from 
iron. 

Dark  Green. — Four  parts  quercitron  and  i  part  logwood 
upon  a  strong  priming  with  vitriol. 

Light  Olive  Green. — Give  the  leather  a  light  bottom  of  Prus- 
sian blue,  and  then  coat  it  with  a  decoction  of  2^  lbs.  of  fustic 
and  y2  lb.  archil  in  20  quarts  of  water. 

Picric  Green. — The  leather  primed  with  Prussian  blue  is 
coated  with  a  solution  of  picric  acid  in  water. 

Lemon  Yellozv. — One  part  turmeric  is  digested  in  4  parts 
alcohol  at  gentle  heat  for  24  hours,  then  diluted  with  water  and 
applied  upon  a  feeble  potash  bottom. 

Barberry  Yellow. — Apply  a  coating  with  a  decoction  of  2^ 
lbs.  of  barberry  root  in  30  parts  water,  to  which  7  ozs.  alum 
free  from  iron  are  added. 

Orange. — A  red  priming  color  is  produced  with  Brazilwood, 
a  yellow  with  fustic;  75  parts  Brazil  wood  and  25  parts  fustic 
give  a  red  orange;  50  parts  of  the  two  an  ordinary  orange; 
25  parts  Brazil  wood  and  75  parts  fustic  a  light  orange. 

Chrome  Yellow. — The  dye  is  first  applied  with  a  solution  of 
1  oz.  of  red  chromate  of  potash  in  one  pint  of  water,  and  is 
next  fixed  by  1  oz.  of  acetate  of  lead  in  one  pint  of  water. 

In  leather  dyeing  it  is  the  custom  to  enter  the  goods  at  the 
maximum  temperature,  viz.,  about  1 12°  F. ;  the  temperature  is 
not  maintained.  The  goods  are  turned  over  by  hand  in  the 
dye-bath,  a  pair  of  skins  at  a  time,  care  being  taken  that  no 
single  pair  shall  remain  long  at  the  bottom  of  the  pile,  from 
one  dozen  to  three  dozen  skins,  according  to  size,  being  dyed 
together  in  one  bath. 

The  manufacture  of  colored  leather  is  a  promising  field. 
The  tanner  who  knows  how  to  get  out  novelties  in  this  line 
may  be  sure  of  success. 

There  are  various  methods  of  dyeing  leather,  such  as  the 


558 


THE  MANUFACTURE  OF  LEATHER. 


English  method,  or  the  one-tray  process ;  the  Continental 
method,  or  two-tray  process. 

The  Continental  method  is  approved  of,  on  account  of  being 
able  to  prepare  the  second  tray  while  the  first  is  in  use.  The 
paddle  method  is  not  recommended,  on  account  of  the  waste  of 
dye  and  liquor,  the  same  applying  to  the  English  tray  method. 

Large  paddles  or  reels  are  used  in  the  paddle  method,  in 
which  as  many  as  twenty-five  dozen  skins  or  more  are  dyed  in 
one  bath,  but  a  certain  amount  of  coloring  matter  is  wasted  by 
being  absorbed  on  the  flesh  side  of  the  skins ;  also  the  variety 
of  shades  obtained  is  greater,  skin  for  skin,  than  when  the  older 
methods  above  mentioned  are  used. 

The  one  great  advantage  in  paddle  dyeing  is  the  saving  of 
labor,  and  it  is  therefore  favored  for  common  classes  of  goods. 

A  large  number  of  skins  are  also  dyed  by  suspending  them 
in  a  vat,  out  of  which  they  can  be  occasionally  raised  for  drip- 
ping by  a  block  and  tackle. 

In  dyeing  leather,  the  use  of  soft,  bright,  clear  water  permits 
the  getting  of  good  colors,  particularly  when  bright  shades  are 
desired. 

Borax  is  the  best  agent  for  softening  and  brightening  water. 

Wood  dyes  possess  the  advantage  of  being  faster  to  light, 
and  not  so  easily  rubbed  off,  and  consequently  more  durable 
than  anilines.  They  are,  however,  dearer,  and  usually  require 
expensive  apparatus  for  their  extraction.  Aniline  colors,  on 
the  other  hand,  are  much  more  easily  applied,  are  cheaper, 
more  brilliant  in  color,  but  not  fast  to  a  strong  light;  many 
fading  rapidly. 

It  is  possible  to  apply  alizarine  colors  to  chrome-tanned 
leather.  In  order  to  fix  alizarine  colors  on  leather,  it  is  neces- 
sary to  apply  considerable  heat ;  for  this  reason  they  are  not 
applicable  to  ordinary  tanned  goods.  Chrome-tanned  leather 
will,  however,  stand  a  high  temperature  without  the  slightest 
damage,  and  for  this  reason  good  results  are  got  with  alizarine 
dyes. 


THE  DYEING  OF  LEATHER. 


559 


INDIGO  CARMINE. 

This  coloring  matter  is  the  product  of  the  action  of  strong 
sulphuric  acid  on  indigo,  and  is  of  use  to  the  leather  manu- 
facturer, making  white  alums  where  perfectly  white  skins  are 
required,  giving  the  same  result  on  this  kind  of  leather  as  ball 
or  liquid  bluing  gives  to  white  cotton  cloth. 

YOUNG  FUSTIC. 

This  coloring  matter  consists  of  the  wood  of  the  sumac  tree, 
and  is  the  product  of  Bavaria  and  Southern  France. 

Young  fustic  comes  in  sticks  about  six  inches  long  and  is  cut 
into  chips,  the  same  as  logwood  or  other  dyewoods. 

This  dyewood  gives  a  greenish  yellow  shade  and  is  used 
largely  by  manufacturers  of  glove  leather.  It  is  important  that 
this  young  fustic  should  not  be  confounded  with  Cuba  or  so- 
called  old  fustic,  which  is  altogether  a  different  article. 

EXTRACT  OF  PEACH  WOOD  OR  RED  WOOD. 

This  is  an  article  which  leather  manufacturers,  to  a  certain 
extent,  have  not  given  the  attention  it  deserves.  For  a  bottom 
to  be  used  for  dark  colors,  on  mineral  tanned,  or  in  fact  any 
tannage,  it  is  a  very  valuable  thing,  giving  a  good  base  on  which 
to  put  the  aniline ;  and  at  the  same  time  it  is  a  saving  from  the 
point  that,  with  this  base,  the  amount  of  aniline  to  be  used  is 
lessened. 

CREME  OF  LOGWOOD. 

One  of  the  handiest  and  most  reliable  of  the  several  articles 
on  the  market  to  replace  the  chip  wood  is  that  sold  as  creme 
of  logwood,  a  concentrated,  clarified  liquor  standing  510  Twd., 
extracted  by  a  new  process  from  the  chips  in  such  a  way  as  not 
to  start  the  tar  or  resinous  matter  from  the  wood,  which  is 
found  in  the  general  run  of  extracts,  and  so  sure  to  make  the 
dyeing  liquor  dull  and  muddy.  Practical  tests  have  proved 
this  creme  of  logwood  to  be  as  cheap,  money  value,  as  the 
chips,  and  at  all  times  insuring  a  uniform  dye  liquor  ready  for 
use  at  a  moment's  notice. 


560 


THE  MANUFACTURE  OF  LEATHER. 


This  product  is  especially  appreciated  by  consumers  who  are 
situated  a  long  distance  from  the  source  of  supply,  on  account 
of  the  great  saving  in  freight,  etc. 

No  fixed  rule  can  be  laid  down  for  the  tanning  and  coloring 
of  hides  and  skins.  They  must  be  treated  according  to  their 
nature. 

In  dyeing  it  is  necessary  to  use  the  woods  in  conjunction  with 
the  anilines. 

In  dyeing  leathers  with  aniline  dyes,  sumac,  bark,  or  gam- 
bier-tanned  leathers  take  neutral  dyes,  but  they  can  also  be 
dyed  with  acid  dyes. 

Alum-tanned  leather  takes  acid  dyes. 

Chrome  tannage  takes  acid  dyes,  or  must  be  treated  with 
sumac  in  order  to  take  neutral  dyes,  which  is  usually  done. 

The  chief  object  in  shoe  and  furniture  leather  is  fastness  to 
light.  The  basic  color  of  all  dyes  used  for  such  leather  is 
phosphine,  which  is  fast  to  light,  air,  acids  and  alkalies. 

The  leather  to  be  dyed  should  be  perfectly  clean  and  free 
from  grease.  In  order  to  accomplish  this,  skins  are  submitted 
to  a  process  known  as  "clearing,"  which  consists  in  passing 
them  through  a  weak  solution  of  potash  and  then  through  a 
weak  sulphuric  acid  bath.  As  there  are  a  great  many  colors 
which  require  sulphuric  acid  to  "set"  them  on  the  leather,  it  is, 
of  course,  not  necessary  to  wash  the  acid  out  until  the  dyeing 
is  finished.  On  the  other  hand,  some  colors  are  very  sensitive 
to  the  action  of  the  acid,  and  hence  it  should  be  washed  care- 
fully out  before  dyeing  with  them. 

Salable  colored  leathers  must  be  uniform  in  color,  and  this 
can  only  be  gotten  by  using  pure  reliable  dyes.  Good  leather 
is  often  spoiled  by  bad  dyes. 

WATERPROOF  COLORS. 

These  are  prepared  as  follows,  according  to  a  process  pat- 
ented in  England  by  Dimitry:  Two  ingredients  are  made  use 
of,  one  consisting  of  bichromate  of  potash,  the  other  of  a  gelatin 
solution.    These  are  mixed  in  suitable  proportions  and  boiled, 


THE  DYEING  OF  LEATHER. 


56l 


after  which  they  are  exposed  to  the  sunlight.  The  mixture  is 
then  combined  with  a  watery  solution  of  aniline  black,  so  as  to 
form  a  thick  pigment.  It  may  also  be  employed  with  other 
aniline  colors,  which  in  this  way  become  both  acid  and  water- 
proof. 

MORDANTS. 

The  few  minerals  which  come  into  practical  use  in  leather 
dyeing,  are  bichromate  of  potash,  sulphate  of  iron,  sulphate  of 
alumina,  sulphate  of  copper,  and  ferrocyanide  of  potassium. 

The  first  two  mentioned  are  used  for  producing  a  dark  or  sad 
effect  on  leather  dyed  with  the  aniline  colors,  or  for  subduing 
the  fiery  tone  of  the  brighter  dyes.  Sulphate  of  copper,  or  as 
it  is  commercially  known,  "  blue  vitriol,"  is  also  used  for  toning 
down  a  color.  These  three  minerals  are  used  either  as  mor- 
dants, or  for  toning  the  color  after  the  aniline  has  been  applied. 

Sulphate  of  alumina,  or  common  alum,  has  exactly  the  op- 
posite effect,  as  it  has  a  tendency  to  sharpen  and  bring  out  the 
brilliancy  of  most  of  the  anilines.  Ferrocyanide  of  potassium 
in  conjunction  with  a  solution  of  ferric  sulphate,  or  copperas, 
produces  a  most  beautiful  mordant  for  any  of  the  blue  dyes. 

In  using  a  mineral  salt  as  a  mordant,  care  should  be  taken 
that  the  salt  in  use  is  properly  fixed  in  the  fibre  of  the  skin  be- 
fore the  aniline  is  applied. 

It  is  also  advisable  to  remove  any  excess  of  mordanting  so- 
lution which  has  not  been  absorbed  by  the  skin,  as  the  presence 
of  the  mineral  salt  in  actual  solution  may  have  a  deterrent  effect 
on  the  penetrating  qualities  of  the  aniline. 

A  mordant  has  served  its  purpose  when  it  has  become  a  com- 
ponent part  of  the  skin,  and  the  subsequent  dyeing  will  result 
more  satisfactorily  if  the  superfluous  mordanting  liquor  is  re- 
moved from  contact  with  the  aniline. 

In  dyeing  with  the  aniline  colors  care  should  be  taken  to 
dissolve  the  dye  thoroughly  and  in  such  a  manner  that  no  sed- 
iment shall  remain  in  the  vessel. 

The  dye  should  never  be  applied  to  the  skins  until  it  has 
been  well  strained. 
36 


562 


THE  MANUFACTURE  OF  LEATHER. 


It  is  also  well  to  repeat  that  uniformity  of  color  can  never 
be  obtained  where  precautions  are  not  taken  in  regard  to 
cleanliness  of  vessels,  etc.,  used  in  preparing  the  dye,  as  a  ves- 
sel which  has  been  used  for  some  other  purpose  may  contain 
traces  of  foreign  matter  sufficient  to  cause  a  chemical  change 
in  the  aniline,  which  would  prevertt  its  going  into  the  leather 
uniformly. 

Evenness  of  color  on  the  skin  can  also  be  facilitated  by  di- 
viding the  given  amount  of  dye  to  a  given  weight  of  leather 
into  3  or  4  portions  ;  for  instance,  if  lOO  lbs.  of  leather  required 
3  lbs.  amaranth  3/R  to  produce  a  desired  shade,  it  would  be 
well  to  divide  the  solution  into  three  different  vessels  and  apply 
the  contents  of  the  second  vessel  as  soon  as  it  is  apparent  that 
the  skins  have  absorbed  the  dye  from  the  first,  and  the  third  in 
sequence  from  the  second,  and  so  on. 

"tanners'  preparation"  for  obtaining  uniform  colored  leather. 

The  continually  increasing  popularity  of  colored  leather  has 
engaged  the  attention  of  tanners  more  closely  in  recent  years 
to  perfecting  the  production  of  this  commodity.  Many 
methods  in  this  connection  have  from  time  to  time  been 
placed  on  the  market,  but  the  vast  majority  have  eventually 
proved  to  be  failures,  the  chief  difficulty  encountered  in  the 
manufacture  of  salable  colored  leather  apparently  being  the 
trouble  experienced  in  successfully  mordanting,  clearing  the 
grain,  and  removing  all  grease  and  animal  matter  from  the 
leather  prior  to  its  reception  of  the  coloring  matter,  it  being  a 
well-known  fact  that  perfect  abstraction  of  all  grease  and  ani- 
mal matter  is  an  absolute  necessity,  if  uniformity  and  clearness 
of  color  are  to  be  obtained.  How  to  accomplish  this  desired 
result  without  injuring  the  leather  is  the  problem  which  com- 
paratively few  tanners  have  been  able  to  solve  with  any  degree 
of  certainty. 

Gilbert  Bros.  &  Co.,  Nos.  202  and  204  Purchase  street,  Bos- 
ton, have  recently  introduced  an  article  of  which  they  are  the 
manufacturers,  designated  "  Tanners'  Preparation,"  which  has 


THE  DYEING  OF  LEATHER. 


563 


been  practically  tested  and  is  now  being  used  by  many  of 
the  most  prominent  manufacturers  of  colored  leather,  both  in 
the  United  States  and  abroad,  with  highly  gratifying  success  in 
removing  the  above-mentioned  difficulties.  The  successful 
production  of  this  "  Tanners'  Preparation  "  was  only  attained 
after  months  of  experimenting,  and  by  the  possession  of 
thoroughly  practical  knowledge  on  the  subject  of  mordant  treat- 
ment of  leather  by  various  compound  salts  and  vegetable  pro- 
ducts, acquired  by  years  of  study  by  the  manufacturers. 

The  process  suggested  by  the  manufacturers  of  this  "Tanners' 
Preparation  "  is  simply  that  it  be  used  as  a  mordant  for  clear- 
ing after  the  skins  are  tanned,  using  about  one  part  to  fifty 
parts  of  water,  regardless  of  the  process  of  coloring  or  the 
colors  used.  Its  principal  advantages  are  that  it  removes  all 
spots,  grease  and  stains,  thereby  giving  an  evenness  of  shade 
and  at  the  same  time  effecting  a  decided  saving  in  the  dyestuff. 

BLEEDING  OR  SMUTTING  OFF  OF  COLORS. 

The  so-called  bleeding  or  smutting  off  of  the  colors  upon 
goods  dyed  causes  the  greatest  annoyances  in  the  dyeing  trade, 
and  such  effects  must  always  be  regarded  as  indicative  of  great 
faults  in  the  application  of  coloring  ingredients,  or  an  injudic- 
ious choice  of  such  substances  for  the  respective  fabrics  treated. 
These  troubles  are  frequently  heard  of  in  dyeing  chrome  black, 
and  by  the  use  of  alizarine  dyes.  Such  accidents  were  less  fre- 
quently heard  of  when  wood  dyes  were  in  general  use,  but  in 
any  case  they  can  only  be  attributed  to  an  imperfect  handling 
of  the  dye  stuffs.  Some  dyers  are  in  the  habit  of  substituting 
cheaper  mordants  and  reviving  agents  for  those  recommended 
by  the  dye  manufacturers,  and  even  of  reducing  the  necessary 
manipulations  of  the  goods  in  order  to  save  time.  In  such 
cases,  this  substitution  might  prove  to  have  an  effect  incompat- 
ible with  the  coloring  bodies,  or  the  fibrous  substances,  and  in 
some  instances  even  cause  decomposition  of  the  coloring  bodies, 
and  prevent  their  fixing  altogether.  The  mordants  and  dye 
stuffs  can  only  upon  perfectly  clean  surfaces  be  correctly  devel- 


564 


THE  MANUFACTURE  OF  LEATHER. 


oped  and  fixed.    If  there  are  noxious  foreign  bodies  present 
*  upon  the  fibrous  substance,  it  can  only  cause  a  great  waste 
of  dye. 

THE  PRACTICAL  DYEING  OF  LEATHER  WITH  ANILINE  COLORS. 

The  accompanying  samples  were  dyed  in  a  practical  way 
and  taken  from  lots  put  through  by  the  different  firms  men- 
tioned. 

They  were  done  in  a  practical  way  and  the  formulas  attached 
may  be  relied  upon  as  being  correct.  The  colors  used  are 
those  that  experience  has  taught  us  as  being  particularly 
adapted  for  leather,  and  from  which  shades  can  be  produced  at 
a  reasonable  cost.  In  dissolving  aniline  colors  it  is  well  to 
have  the  water  heated  to  about  1800  F. ;  the  color  added  and 
allowed  to  go  into  solution ;  then  bring  to  boil  for  several 
minutes. 

Sample  No.  I. 

RUSSIA  CALF  COMBINATION  TANNAGE. 

Tanned  and  colored  by  Bernard  Freidman  &  Co.,  Danvers,  Mass. 
For  30  feet  stock  3  skins,  used  3  oz.    Leather  brown  F.    Run  in  pin  wheel  % 
hour.    Color  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Tanned  and  colored  by  E.  A.  Muller,  North  Cambridge,  Mass. 

Ox-blood  shade.  5  doz.  small  calf  skins.  Run  10  minutes  in  wheel  with  50  gal- 
lons water  to  dampen  out  and  soften  leather;  temperature  900  F.;  then  handle  as 
follows : 

\)/{2  lbs.  Tartar  Emetic.    Run  15  minutes. 

2  lbs.  Amaranth,  3-R,  added  in  four  separate  parts.  First  part  run  10  minutes  and 
succeeding  ones  15  minutes  each. 

Then  add  12  ozs.  Amaranth,  i-R.      1  „      , ,  , 

V    Kiln    1-  hniir 


"      "     4  "    Chocolate  brown  O.  J 
"      "    3  lbs.  Palermo  fig  soap. 
"     "    5  lbs.  pure  egg  yolk. 
"      "    5  ozs.  bichromate  potash. 
Add  in  above  order. 

Dye  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  II. 


RUSSIA  CALK — COMBINATION  TANNAGE. 


Page  564. 


THE  DYEING  OF  LEATHER. 


565 


Sample  No.  III. 

CLOVE  SHEEP  LEATHER — ATTEAUX  O.  B.  MINERAL  TAN. 
Natural  color  of  the  leather  as  it  comes  from  the  tan. 
Tanned  by  F.  C.  Rose,  Gloversville,  N.  Y. 


Sample  No.  IV. 

SHEEP  SKIN — SUMAC  TANNAGE. 

Tanned  and  colored  by  A.  C.  Lawrence  &  Co.,  Peabody,  Mass. 
For  large  skins  1  oz.  leather  blue  No.  1  to  dozen  skins. 
Color  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  V. 

TANNAGE — ATTEAUX  O.  B.  MINERAL  TAN. 
For  I  dozen  pickle  sheep,  6  oz.  fulling  red  for  leather.    Run  %  hour- 
Tanned  and  colored  by  F.  C.  Rose,  Gloversville,  N.  Y. 
Dye  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  VI. 

TANNAGE — ATTEAUX  O.  B.  MINERAL  TAN. 

For  I  doz.  Goat  Skins  (Russian). 

Light  bottom  pure  fustic  extracts  51",  run  10  minutes. 

3  ozs.  dark  green  M.,  l}»  ozs.  amaranth  I-R.,  run  15  minutes. 

Tanned  and  colored  by  Weber  Leather  Co.,  Lynn,  Mass. 

Dye  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  VII. 
INDIA  TANNED  GOAT. 
Colored  and  finished  by  Donohue  Bros.,  Lynn,  Mass. 

For  1  doz.  skins,  cleared  in  borax  and  sal  soda  water,  dyed  with  4  ozs.  nut  brown 
"  O,"  with  a  very  light  chrome  on  top. 

Color  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  VIII. 

SHEEP  SKIN. 

Tanned  with  the  Atteaux  O.  B.  Mineral  Tan. 
Tanned  and  colored  by  F.  C.  Rose,  Gloversville,  N.  Y. 

Colored  as  follows:  14  doz.  skins — 2}^  lbs.  yellow  II.,  2  lbs.  ext.  fustic  solid. 
Fat  liquored  as  follows :    A  mixture  40  lbs.  light  English  sod  oil,  20  lbs.  Palermo 
fig  soap,  50  galls,  water. 

Used  %  pail  of  above  mixture  to  each  dozen  skins. 
Dye  furnished  by  F.  F.  Atteaux  &  Co.,  Boston,  Mass. 


566 


THE  MANUFACTURE  OF  LEATHER. 


Sample  No.  IX. 
DARK  GREEN  INDIA  TANNED  GOAT  SKIN. 
Colored  and  finished  by  P.  D.  Fgan,  Salem,  Mass. 

For  I  doz.  skins:  I  oz.  Bichromate  Potash,  10  minutes;  2  ozs.  Direct  Green  "  B," 
10  minutes;  1  oz.  Bichromate  Potash,  10  minutes;  %  oz.  Copperas,  10  minutes. 
Dye  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  X. 
PICKLE  SHEEP  SKIN  TANNAGE — TWO  BATH  CHROME. 

Dark  ox  blood. 

For  1  dozen  sheepskins.  Put  skins  in  20  gallons  water  at  no0  F.  Dissolve  I  lb- 
fustic  extract  and  2  lbs.  peachwood  extract  in  boiling  water.  Stir  while  in  water  and 
add  above.  Run  ^  hour.  Then  dissolve  6  ozs.  amaranth  3-R — 1^  oz.  malachite 
green  in  1  gallon  water.  Then  add  another  gallon  boiling  water  and  I  oz.  bichromate 
of  potash. 


Sample  No.  XI. 
FOR  I  DOZEN  SHEEP  SKINS — HEMLOCK  TANNAGE. 

Tanned  and  colored  by  Geo.  E.  Hayes,  Peabody,  Mass. 

4  ounces  fulling  red.  Run  20  minutes.  Then  add  ^  ounce  bichromate  potash 
and  run  10  minutes  longer. 

Color  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


Sample  No.  XII. 
GOAT  SKIN — ATTEAUX,  O.  B.  MINERAL  TAN. 

Tanned  and  colored  by  Weber  Leather  Co.,  Lynn,  Mass. 
For  500  lbs.  leather. 

5  lbs.  pure  extract  fustic,  51°,  7  minutes. 
2  lbs.  haematoxylin  powder,  7  minutes. 
1  lb.  6  oz.  anilin  yellow,  7  minutes. 
13  oz.  chrome  brown,  B,  7  minutes. 
4  oz.  golden  orange,  7  minutes. 
12  oz.  bichromate  potash,  7  minutes. 

Before  adding  each  of  above  they  were  dissolved  in  3  buckets  water. 

Fat  liquor,  1o  pail  pure  egg  yolk. 

Dye  furnished  by  F.  E.  Atteaux  &  Co.,  Boston,  Mass. 


The  following  list  of  aniline  and  alizarine  colors  that  work  to 
advantage  on  leather  and  are  being  used  in  a  general  way 
among  leather  manufacturers.  They  are  furnished  by  F.  E. 
Atteaux  &  Co.,  Boston,  Mass. : 


THE  DYEING  OF  LEATHER. 


567 


Amaranth  1  /  R. 

Sienna  Brown  Y. 

Sun  Yellow. 

"  2/R. 

Middleton  Brown. 

Azo  Yellow. 

3/R. 

Leather  Brown,  Extra. 

Leather  Yellow  A. 

Leather  Red  1  /  B. 

Bismarck  Brown  Y  S. 

Fast  Yellow  F. 

Bismarck  Brown  R.  S. 

Acid  Yellow  F. 

Safranine. 

Mokka  Brown. 

Mimosa  Yellow. 

Eosine. 

Cutch  Brown. 

Chrysodine. 

Fast  Red. 

Dominion  Brown. 

Lemon  Yellow. 

Archil  Substitute. 

Terra  Cotta  Brown. 

Boston  Yellow. 

Grenat. 

Mahogany  Brown. 

Naphthol  Yellow. 

Russia  Red. 

Acid  Brown  R. 

Leather  Yellow  No.  15 

Imperial  Red. 

Acid  Brown  B. 

Orange  I. 

Fuchsine  F.  B. 

Acid  Brown  G. 

"      I  I. 

Maroon  for  Leather. 

Nankin  Brown  Lumps. 

"  IV. 

Bordeaux  Extra. 

Brown  B  S  R. 

"  D. 

Blood  Red. 

Leather  Brown  B  S  R. 

Chrome  Orange. 

Olive  1 1 . 

Chocolate  Brown  0. 

Vici  Drab. 

Norwood  Olive. 

Chocolate  Brown  270. 

Bluish  Grey. 

Phloxine. 

Brown  361  for  Leather. 

Silver  Grey. 

Violets  1    R  to  5  /  R. 

Olive  Brown  K. 

Ink  Black. 

Violets  1 ;  B  to  6  /  B. 

Seal  Brown. 

Acid  Black  L. 

Acid  Violet. 

Nankin  Brown  R. 

Pure  Black. 

Malachite  Green. 

Leather  Brown  No.  200. 

G  G  S  Black. 

Fast  Green. 

Methylene  Blue. 

Nigrosine  P. 

Brilliant  Green. 

Guernsey  Blue. 

Nigrosine  Extra. 

China  Green. 

Fast  Blue. 

Nigrosine  B. 

Fmerald  Green. 

Gentianine  Blue. 

Indieotine. 

Victoria  Green. 

Nicholson  Blue. 

Blue  No.  444. 

Oark  Green  S. 

Soluble  Blue. 

Alizarine  Yellow, 

Pure  Blue. 

Alizarine  Brown  Y. 

"  Blue. 

Alizarine  Brown  0. 

"  Orange. 

"  Mordant. 

Red  W.  B. 

"  Violet. 

Curcumine. 

Red  B. 

Phosphine. 

Citronine. 

Diamond  Brown  M. 

Yellow  849. 

Vesuvine  R. 

Sienna  Brown  R. 

Flesh  Yellow. 

FORMULA  FOR  OBTAINING  THE  CORRECT  OX-BI.OOD  SHADE  ON  COMBINATION 
TAN  OR  STRAIGHT  GAMBIER  TANNED  CALF  SKINS,  FURNISHED  BY 
F.  E.  AT1EAUX  &  CO.,  BOSTON,  MASS. 

I  dozen  calf  skins  averaging  10  feet  each. 

Take  10  lbs.  hypernic  chips;  boil  thoroughly  and  strain 
through  cheese  cloth  or  bagging.  Put  skins  in  wheel  with 
sufficient  warm  water  (temperature  8o°  F.)  to  float  them. 
Add  the  hypernic  solution  by  degrees  while  the  wheel  is  in 


Page  568. 


THE  DYEING  OP  LEATHER. 


569 


Sample  No.  14  is  a  specimen  of  quebracho-tanned  leather 
which  is  also  furnished  by  A.  Klipstein  &  Co.,  New  York. 

They  are  the  largest  importers  of  quebracho  extract  in  this 
country,  and  carry  a  large  stock  at  their  main  warehouse  in 
New  York  and  at  their  various  branches. 

The  advantages  of  using  quebracho  may  be  summed  up  as 
follows : 

1.  It  makes  the  most  pliable  leather  because 

2.  It  tans  all  the  way  through  the  hide,  consequently 

3.  It  increases  the  weight  of  leather  obtainer. 

4.  It  tans  more  rapidly,  and 

5.  It  tans  more  denser  solutions  than  any  other  tanning 
agent. 

6.  It  is  the  cheapest  tannage  known. 

CALF  LEATHER  DYEING. 

Calf  is  among  leathers  what  silk  is  among  textile  fibres,  for  it 
is  readily  dyed  of  all  shades.  There  are,  however,  certain 
difficulties  which  many  manufacturers  never  overcome,  and  im- 
portant among  these  are  those  which  arise  from  improper  pre- 
paration of  the  leather.  In  small  works  the  preliminary 
softening  is  effected  by  a  short  soaking  in  sufficient  luke-warm 
water  to  cover  the  leather,  followed  by  an  hour's  pounding 
with  oak  stamps.  Water  at  1040  F.  is  then  run  into  the  vat,  and 
the  goods  are  thoroughly  handled  for  some  time  ;  the  turbid 
water  is  drained  off,  and  the  stamping  and  handling  repeated 
until  the  right  degree  of  slipperiness  has  been  attained. 
Tumblers  replace  the  stamps  in  larger  works.  After  the  soften- 
ing process  the  leathers  are  made  up  into  pairs,  one  leather 
being  stretched  grain  downwards  on  a  glass  or  zinc  table,  and 
another  stretched  on  the  top  of  this  one  with  the  grain  up- 
wards ;  this  affords  an  opportunity  for  striking  out  certain 
blemishes,  and  is  also  conducive  to  economy  of  dyestuffsr 
since  the  flesh  sides  are  not  exposed  in  the  dye-bath. 

The  water  for  the  dye-bath  should  be  acidulated  with  acetic 
acid  to  avoid  the  hardening  effect  of  calcareous  matters  on  the 


57Q 


THE  MANUFACTURE  OF  LEATHER. 


leather.  For  light  shades,  alum  or  bichromate  of  potash  are  the 
mordants;  for  medium  tones,  a  purer  acetate  of  iron  is  used; 
whilst  pyrolignite  of  iron  (about  150  B.),  nitrate  of  iron  (300 
B.),  or  sulphate  of  iron  (300  B.),  serve  for  the  darker  shades. 
Alum  is  but  little  used.  Bichromate  of  potash  is  applied  to  the 
extent  of  10-20  grammes  (154.32  to  308.64  grains)  per  pair  of 
leathers,  the  whole  being  generally  added  at  once.  The  leather 
is  well  handled  in  the  bath  for  10  minutes,  and  transferred  to  a 
fresh  bath,  to  which  a  small  portion  of  the  dyestuff  has  been 
added  ;  into  a  second  fresh  bath  the  remainder  of  the  dyestuft 
is  introduced,  and  the  dyeing  is  completed  therein.  If  a 
smaller  proportion  of  bichromate  is  being  used,  the  dyeing  can 
be  completed  in  the  first  bath.  When  iron  mordants  are  used, 
acetic  acid  must  be  present  in  the  mordant  bath,  and  it  is  ad- 
vantageous to  use  the  feeblest  iron  salts  for  grounding.  A 
dilute  iron  mordant  (the  purer  acetate  at,  2°  B.,  or  pyro- 
lignite at  about  io°  B.)  saddens  gradually,  whilst  a  stronger 
liquor  is  very  active  and  "  goes  quickly  on,"  so  that  uneven 
dyeing  easily  results.  Cold-washing  after  the  iron  mordant  is 
to  be  avoided,  since  the  leather  is  thereby  hardened.  The 
foregoing  mordants  are  for  basic  dyestuffs,  acid  dyestuffs  not 
being  amenable  to  such  treatment. 

The  following  list  of  leather  dyes  is  given : 


BASIC. 


ACID. 


Auramine. 
Phosphine  N. 
Philadelphia  yellow. 
Leather  yellow. 
Aniline  yellow. 
Phosphine  P.  H. 
New  Phosphine. 
Phosphine  superfine, 
Thioflavine  T. 
Xanthine. 
Canelle. 
Leather  red. 
Grenadine. 
Camelia  B. 


Quinoline  yellow. 
Naphthol  yellow. 
Curcurmen. 
India  yellow. 
Azo  acid  yellow. 
Orange  I  I. 
Mandarin  G.  extra. 
Ponceau  B  O.  extra. 
Poneeau  3  R  B. 
Scarlet  for  leather. 
Ponceau  B  extra. 
Pure  blue. 
China  blue. 
Bavarian  blue. 


THE  DYEING  OF  LEATHER. 


571 


Russia-leather  red. 
Bismarck  brown. 
Manchester  brown  P  S. 
Vesuvine. 
Cachou  brown  D. 
Leather  brown  A  and  B. 
Malachite  green. 
Diamond  green. 
Methylene  blue. 
Methylene  dark  blue  B  R. 
Coal  black. 
Leather  black. 
Leather  black  4252. 


Fast  blue  for  leather. 
Acid  green. 
Guinea  green. 
Fast  brown  O. 
Fast  brown  3  B. 
Eosin. 
Erythrosin. 
Phloxin. 
Rhodamine. 
Nigrosin. 


THE  DYEING  OF  LEATHER  FOR  SHOES. 


A  largely  increased  demand  for  brown  shoe  leather  has  been 
evident  for  the  last  few  years.  Leather  for  this  purpose  is 
manufactured  principally  from  calf  skin  for  the  better  article, 
and  from  sheep  skin  for  the  inferior.  Sheep  skins  already 
tanned  are  largely  imported  from  Australia  and  New  Zealand 
into  England.  The  tanning  agent  in  this  case  is  the  bark  of  the 
various  species  of  acacia,  natives  of  Australia,  which  contain 
the  deep  red  mimotannic  acid,  and  consequently  the  tannage  is 
of  a  reddish  tint.  These  skins  are  capable  of  being  dyed  really 
beautiful  colors,  and  when  carefully  dyed  and  finished  the 
better  qualities  make  a  fine  article  at  a  comparatively  low  price, 
but,  of  course,  with  nothing  like  the  resistance  to  wear  of  a  calf 
skin.  The  process  for  preparing  tanned  calf  skins  for  dyeing  is 
as  follows:  During  the  tanning  process  a  large  quantity  of 
ellagic  acid  is  almost  invariably  precipitated,  and  intimately 
mixed  with  the  fibres  of  the  skin.  This  is  technically  known 
as  bloom,  and  must  be  removed  before  dyeing,  or  very  poor 
uneven  shades  will  result. 

Previous  to  this  operation  the  goods  are  shaved  down  to  the 
required  substance.  They  should  then  be  tumbled  with  warm 
water  in  a  revolving  drum  to  break  and  soften  them,  and  this 
operation  also  removes  a  portion  of  the  bloom.  The  skins  are 
next  taken  out  one  at  a  time  and  placed  on  a  marble  or  glass 
slab,  each  skin  being  knocked  out  perfectly  flat  and  level  so 


572 


THE  MANUFACTURE  OF  LEATHER. 


that  it  attaches  itself,  as  it  were,  to  the  slab  This  is  done  by 
the  men  with  what  is  known  as  a  brass  slicker.  With  this  tool 
the  grain  of  the  skin  is  pushed  out  smooth  until  it  presents  an 
even  surface.  The  grain  of  the  skin  is  now  scoured  with  a 
sort  of  brush  made  by  tying  up  a  piece  of  brass  into  a  suitable 
shape;  by  this  process  and  a  repetition  of  the  slicking  out  the 
bloom  is  removed  from  the  skin.  The  skins  are  next  worked 
in  a  warm  and  very  weak  solution  of  soda  crystals  to  remove 
surface  grease.  They  are  then  taken  to  a  bath  of  sulphuric  acid 
of  about  f  per  cent,  strength  and  worked  about  in  this  for  ten 
minutes,  after  which  they  are  knocked  about  in  running  fresh 
water  until  they  no  longer  taste  of  acid,  or  if  to  be  dyed  with  acid 
coloring  matters,  only  slightly  so.  After  draining  on  a  horse 
or  trestle  for  some  time  the  skins  are  slicked  out  on  the  grain 
side  until  they  present  an  even  surface  ;  they  are  then  placed 
flesh  side  together  in  pairs  ready  for  the  dye-bath. 

Dyeing  Calf  Skins  for  Shoe  Work. — It  will  readily  be  seen 
from  the  great  difference  in  weight  of  similar-sized  skins  and  by 
the  fact  that  only  the  grain  side  of  the  skin  must  necessarily  be 
dyed,  that  it  is  impossible  to  calculate  percentages  of  coloring 
matter  simply  to  weight  of  skins.  One  must  perforce  use 
different  percentages  for  different  classes  and  sizes  of  skins,  also 
for  different  tannages;  the  correct  proportions  for  different 
tannages,  etc.,  being  only  learned  by  experience.  The  acid 
coloring  matters  are  so  easily  applied  to  leather  and  the  results 
are  so  satisfactory,  that  they  are  to  a  large  extent  replacing 
other  classes  of  coloring  matters. 

With  the  following  three  colors  almost  any  shade  of  brown 
which  will  be  required  for  shoe  purposes  may  be  obtained, 
viz.:  Azo  flavine  RS,  fast  brown,  blue  black  (induline). 

For  instance,  by  combination  of  eight  parts  azo  flavine  and 
half  part  fast  brown,  the  light  Russian  brown  shade,  which  is  so 
much  worn,  may  be  produced. 

Four  parts  azo  flavine,  one  part  fast  brown  and  half  part  blue 
black  will  produce  a  medium  shade  of  brown. 

Four  parts  azo  flavine  and  two  parts  fast  brown  produce  a 
red  brown. 


THE  DYEING  OF  LEATHER. 


573 


To  produce  a  chocolate  or  dark  brown,  one  part  blue  black 
and  one  part  fast  brown  are  applied  to  the  skins,  four  parts  azo 
flavine  and  one  part  fast  brown  being  afterwards  added  to  the 
same  bath. 

The  varieties  of  colored  leather  used  for  shoes  are  becoming 
more  marked  each  year.  From  solemn  black  to  sober  brown 
was  the  first  step,  and  then  the  browns  grew  lighter  and  lighter 
until  they  reached  the  custard  tint.  After  the  browns  came  the 
reds  and  the  ox-blood  tints  were  the  thing,  and  now  we  are  drift- 
ing into  blue  and  green  tints  foi  ladies'  shoes.  These  fancy 
colors  all  make  money  while  novel,  but  they  are  liable  to  go 
out  of  fashion  any  day.  However  the  bold  spirits  who  are  able 
to  furnish  promptly  whatever  colored  leather  is  wanted  will 
make  the  money  if  agile  enough  to  return  to  beaten  paths  at 
the  right  time. 

DIRECTIONS  FOR  OBTAINING  CORRECT  OX-BLOOD  SHADE  ON  ONE  DOZEN 
CHROME  TANNED  CALFSKINS. 

The  following  instructions  are  given  by  F.  E.  Atteaux  &  Co., 
the  well-known  dye-stuff  house  of  Boston,  Mass. : 

Dissolve  i  lb.  extract  of  fustic  and  2  lbs.  extract  of  peach- 
wood  in  boiling  water.  Put  skins  in  the  wheel  with  30  gal- 
lons of  water,  temperature  1  io°  F. ;  stir  while  in  motion  and 
add  above  decoction  by  degrees,  either  through  open  door  of 
wheel  or  through  funnel  attached  to  journal  bearings  of  wheel. 
Run  for  half  hour.  Then  dissolve  in  bucket  12  ozs.  amaranth 
3/R  with  1  gallon  boiling  water  and  add  8  ozs.  white  glycerine ; 
stir  constantly  while  adding  boiling  water  and  glycerine.  Then 
add  another  gallon  of  boiling  water  and  hold  pail  under  steam 
pipe,  stirring  all  the  time  until  the  aniline  is  thoroughly  dis- 
solved. 

Have  another  bucket  ready,  over  the  top  of  which  is  spread 
a  piece  of  cheese-cloth  or  fine  bagging,  and  allow  this  mixture 
to  run  through  the  screen.  Then  cool  off  with  cold  water  to 
no°  F.  and  apply  same  to  skins  in  wheel  in  the  same  manner 
as  the  preparation  first  mentioned,  doing  this  while  the  wheel 


574 


THE  MANUFACTURE  OF  LEATHER. 


is  in  motion.  Run  them  half  hour,  then  take  out  skins  and 
dip  separately  in  barrel  of  clean  water.  Run  off  waste  dye- 
liquor  and  wash  wheel  out.  Dissolve  2  ozs.  bichromate  of 
potash  in  water  and  add  to  skins  as  the  other  liquors  were 
added.  Run  wheel  for  fifteen  minutes,  then  take  skins  out  and 
lay  away  grain  to  grain  for  half  hour  before  striking  out.  In 
setting  grain  use  brass  slickers. 

Note. — Do  not  at  any  time  during  the  operation  allow  the 
temperature  of  the  water  in  the  wheel  to  fall  below  ioo°  F. 

Do  not  stop  the  wheel  under  any  circumstances  until  the  dye 
has  been  in  for  at  least  ten  minutes. 

Be  sure  all  utensils  are  perfectly  clean. 

Shade  of  color  desired  is  a  matter  of  judgment.  A  greater 
depth  of  color  can  be  obtained  by  increasing  the  strength  of 
the  mordant  or  the  first  liquor  as  described  above. 

For  a  light  shade  of  ox-blood,  increase  the  proportion  of 
fustic  extract  and  use  less  of  the  peachwood. 

If  sumac  extract  be  used  for  a  mordant  in  place  of  the  one 
we  have  mentioned  above,  use  I  lb.  of  the  extract  to  i  dozen 
calfskins. 

All  dye,  etc.,  should  be  thoroughly  boiled  and  should  be 
cooled  with  water  before  being  put  in  the  wheel. 

It  is  of  the  greatest  importance  to  keep  the  skins  in  motion 
while  adding  any  of  the  dyeing  material. 

METHODS  OF  DYEING   LEATHER  USED  IN  GERMANY  PREPARING   THE  DYE 

BATH . 

When  a  leather  has  been  mordanted  with  a  mordant  of  de- 
termined concentration,  a  certain  quantity  of  mordant  is  present 
upon  a  definite  surface  of  the  leather,  for  instance  upon  a 
square  inch,  and  with  the  proper  use  of  the  mordant  this  pro- 
portion is  the  same  upon  the  entire  surface  of  the  leather,  i.  e., 
each  surface  of  one  square  inch  contains  the  same  amount  of 
mordant. 

However,  a  determined  quantity  of  the  mordant  will  also  fix 
a  definite  quantity  of  coloring  matter  and  with  a  uniform  distri- 


THE  DYEING  OF  LEATHER. 


575 


bution  of  the  mordant  over  the  entire  surface  of  the  leather  the 
intensity  of  the  color  will  be  alike  everywhere. 

Hence  it  will  be  seen  that  the  depth  of  a  certain  color  is  de- 
pendent on  the  quantity  of  mordant  present  upon  a  definite 
surface;  i.  e.,  if  a  mordant  of  determined  concentration  is  ap- 
plied to  the  surface,  the  result  of  dyeing  will  be  a  certain 
definite  shade  of  the  respective  colors.  With  a  mordant  of 
greater  concentration  the  result  will  be  a  darker  shade  of  the 
same  color,  while  with  a  more  dilute  mordant  a  lighter  shade 
of  the  same  color  will  be  obtained. 

When  working  with  a  substantive  coloring  matter,  i.  e.,  a 
coloring  matter  which  combines  with  the  fibre  of  the  leather 
without  the  necessity  of  using  a  mordant,  a  saturated  solution 
will  give  the  darkest  tone  the  respective  coloring  matter  is 
capable  of  producing,  and,  on  the  other  hand,  the  more  the 
solutions  are  diluted  the  lighter  the  shades  will  be. 

It  is  well  known  that  in  dyeing  leather,  and  especially  in 
dyeing  kid,  such  advancement  has  been  made  that  with  one 
and  the  same  color,  for  instance,  pigeon  gray  or  fawn,  such 
numerous  modifications  may  be  produced  that  by  laying  the 
dyed  leathers  alongside  one  another,  a  complete  scale  of 
colors,  from  the  most  delicate  gray  or  light  brown  to  the 
darkest  gray  or  brown,  may  be  established. 

Now  in  order  not  to  work  at  hap- hazard  and  not  to  make 
the  hitting  of  a  certain  desired  color  dependent  on  the  skill  of 
the  workman,  it  is  of  importance  to  find  means  by  which  the 
shades  to  be  produced  may  once  for  all  be  fixed. 

If,  for  instance,  a  color  is  to  be  produced  which  is  to  be 
formed  by  fixing  the  coloring  matter  of  a  wood  upon  the 
leather  by  means  of  tin  oxide  or  alumina,  a  definite  tone  of 
color  may  be  obtained  by  working  according  to  one  or  the 
other  of  the  following  processes  : 

A  mordant  of  tin-salt  containing  an  accurately  determined 
quantity  of  tin-salt  is  prepared  as  follows :  Dissolve  an  accur- 
ately weighed  quantity  of  the  salt  in  water,  and  apportion  this 
quantity  to  a  corresponding  number  of  skins.    Instead  of 


576 


THE  MANUFACTURE  OF  LEATHER. 


directly  weighing,  the  content  of  tin-salt  in  the  mordant  might 
also  be  determined  by  means  of  an  areometer. 

Now,  theoretically,  with  the  use  of  a  solution  containing  an 
accurately  determined  quantity  of  tin-salt  a  definite  tone  of 
color  should  be  formed,  but  in  the  practice  it  is,  for  several 
reasons,  scarcely  possible  to  obtain  satisfactory  results  by  this 
method. 

On  the  one  hand,  it  is  not  so  easy  as  it  would  appear  at  the 
first  glance,  always  to  weigh  with  the  utmost  accuracy  the 
same  quantities  of  a  body,  or  to  determine  with  positive  exact- 
ness the  density  of  a  solution,  as  is  absolutely  necessary  in  this 
case,  while  on  the  other,  the  skins  to  be  treated  are  not  all  of 
the  same  size,  and  even  if  worked  alike  their  power  of  absorb- 
ing fluids  may  vary.  Furthermore  it  must  be  taken  into  con- 
sideration that  tawed  leather  already  contains  a  body,  alumina, 
which  possesses  the  property  of  fixing  coloring  matters,  and 
that  the  animal  skin,  even  in  the  form  of  leather,  is  capable  of 
separating  certain  quantities  of  coloring  matters,  though  not 
substantive  ones,  which  it  retains  so  tenaciously  that  they 
cannot  be  removed  even  by  long-continued  washing.  Hence 
with  the  use  of  mordants,  the  content  of  tin-salt  of  which  has 
been  accurately  determined,  quite  definite  tones  cannot  be  pro- 
duced with  absolute  certainty,  there  being  many  difficulties  in 
the  way  of  the  practical  execution  of  this  method,  though  theo- 
retically it  is  correct. 

The  other  method  consists  in  using  solutions  of  coloring 
matters  of  an  exactly  determined  concentration.  In  this 
manner  it  is  certainly  possible  to  obtain  satisfactory  results,  the 
process  having  besides  the  advantage  of  being  suitable  for 
substantive  colors  as  well  as  for  colors  which  can  only  be  fixed 
by  a  mordant.  This  process  is  based  upon  the  fact  that  a  fluid 
is  capable  of  dissolving  only  a  certain,  exactly  determined, 
quantity  of  a  body. 

By  boiling,  for  instance,  Brazil  wood  in  water,  a  certain 
quantity  of  the  coloring  matter  is  dissolved,  but  afterwards  no 
more  will  pass  into  solution  even  if  boiling  be  continued  for 


THE  DYEING  OF  LEATHER. 


577 


any  length  of  time.  Such  a  solution  is  saturated,  and  in  this 
case  is  called  a  hot  saturated  solution. 

By  cooling  a  hot-saturated  solution  to  the  ordinary  tempera- 
ture, a  certain  quantity  of  the  body  held  in  solution  re-separates, 
and  we  have  then  what  is  called  a  cold-saturated  solution.  The 
ordinary  temperature  of  living  rooms  is  about  6o°  to  650  F., 
and  it  may  be  assumed  that  within  these  temperatures  a  cold- 
saturated  solution  of  coloring  matter  in  water,  which  has  been 
prepared  by  boiling  and  then  allowed  to  cool,  always  contains 
t  ie  same  quantities  of  coloring  matter. 

Hence,  by  preparing  a  decoction  of  a  coloring  matter  and 
allowing  it  to  cool  to  the  ordinary  temperature,  a  dye-bath  is 
obtained  which  always  contains  the  same  quantities  of  coloring 
matter.  By  dyeing  mordanted  leather  in  this  dye-bath,  which 
may  be  used  cold  or  warm,  the  same  shade  of  color  is  always 
obtained. 

Now,  it  is  not  difficult  to  prepare,  with  the  assistance  of  such 
cold  saturated  dye-bath,  fluids  which  produce  determined 
lighter  shades  of  color,  it  being  only  necessary  for  this  pur- 
pose to  dilute  the  bath  according  to  a  definite  system. 

Dilution  is  best  effected  by  preparing  the  dye-bath  according 
to  100  parts.  By  adding  to  95  quarts  dye-bath  5  quarts  water, 
a  bath  is  obtained  which  contains  ^  less  coloring  matter  than 
the  original  cold  saturated  solution  ;  by  adding  to  90  quarts 
dye-bath  10  quarts  water,  a  bath  is  obtained  which  contains  ^ 
less  coloring  matter,  and  so  on.  Hence,  in  this  manner,  by 
mixing  95,  90,  85,  80,  etc.,  quarts  of  dye-bath  with  5,  10,  15, 
20,  etc.,  quarts  of  water,  baths  are  obtained,  the  amount  of 
coloring  matter  of  which  decreases  according  to  a  certain  pro- 
portion, and  in  dyeing  these  fluids  will  yield  definite  tones  of 
color. 

By  dyeing  with  such  fluids  a  sample  scale  of  leather,  it  can 
be  immediately  ascertained  by  comparison  in  what  proportion 
the  dye-bath  has  to  be  diluted  for  the  production  of  a  certain 
shade  according  to  sample.  By  the  use  of  such  a  systemati- 
cally arranged  color-scale  beautiful  results  are  readily  obtained 
37 


578 


THE  MANUFACTURE  OF  LEATHER. 


when  coloring  matters  by  themselves  are  used  for  dyeing  a 
leather,  the  matter  being,  however,  more  difficult  with  blended 
colors  which  are  not  produced  by  one  coloring  matter  alone. 
However,  even  in  this  case  it  will  not  be  difficult  for  the  ex- 
perienced workman  when  a  dyed  sample  is  submitted  to  him  to 
select  the  coloring  matters  required  for  the  production  of  the 
respective  color.  With  a  mixture  of  solutions  prepared  in  ac- 
cordance with  the  method  given  above  he  may  make  an  ex- 
periment, and  from  the  shade  obtained  he  will  at  once  know 
whether  he  has  hit  the  proper  proportion  or  whether  there  is 
too  much  of  one  or  the  other  coloring  matter,  and  in  most 
cases  scarcely  more  than  two  trials  will  be  required  in  order  to 
imitate  even  the  most  difficult  colors. 

When  working  with  ready-made  dye-stuffs,  for  instance  ani- 
line colors,  it  is  best,  on  account  of  their  great  coloring  power, 
not  to  prepare  the  standard  fluids  in  the  above-described  man- 
ner by  making  a  saturated  solution  in  water  and  then  diluting 
the  solution.  A  solution  of  water-soluble  blue  prepared  in 
that  manner  would,  for  instance,  appear  black,  and  require 
enormous  quantities  of  water  for  dilution  to  make  a  fluid  suita- 
ble for  dyeing.  For  this  reason  it  is  preferable  to  weigh  out, 
according  to  the  coloring  power  of  the  dye-stuff,  a  certain 
quantity  of  it,  say,  o. I,  0.3,  0.7,  and  so  on,  to  3  ounces,  and 
dissolve  this  quantity  in  I  quart  of  water.  Mark  the  solution 
thus  obtained  with  100,  as  being  the  most  powerful  color,  and 
m'x  2V  >  A>  i\>  and  so  on,  quart  of  it  with  and  so  on, 

quart  of  water. 

TONING  FLUIDS. 

In  many  dyeing  establishments  it  is  customary  to  treat  the 
leathers,  after  the  application  of  the  mordants,  with  solutions 
of  copperas,  sulphate  of  zinc  or  sulphate  of  copper,  or  of  alum, 
potassium  chromate,  etc.  This  operation  may  suitably  be 
called  toning  the  colors,  and  the  fluids  used  for  the  purpose, 
toning  fluids. 

The  mode  of  action  of  the  toning  fluids  varies  much  accord- 


THE  DYEING  OF  LEATHER. 


579 


ing  to  the  constitution  of  the  leather  and  the  coloring  matter 
used,  and  in  certain  cases  may  be  designated  as  the  actual 
development  of  the  color  itself,  while  in  others  it  simply 
causes  a  corresponding  change  in  the  constitution  of  the  tone 
of  color.  It  may  here  be  remarked  that  colors  produced  with 
the  use  of  aniline  colors  alone,  do  not  require  toning. 

If,  for  instance,  a  leather  has  been  treated  with  logwood  de- 
coction, only  a  pale  gray-blue  coloration  is  obtained,  the  blue- 
black  color  appearing  only  after  pouring  copperas  solution 
over  the  leather.  In  this  case  it  may  be  said  that  the  toning 
fluid  exerts  a  dyeing  action,  and  it  might  also  be  designated 
as  a  developing  fluid. 

A  toning  fluid  consisting  of  potassium  chromate  solution 
acts  in  a  similar  manner,  a  deep  black  being  immediately 
produced  when  applied  to  leather  dyed  with  logwood.  If 
tanned  leather  be  brought  in  contact  with  a  fluid  containing 
copperas,  it  is  immediately  colored  bluish-blackish  and,  with 
the  use  of  more  concentrated  copperas  solution,  even  deep 
black,  the  reason  for  this  being  that  the  copperas  forms  a 
black  combination  with  the  tannin.  Hence  copperas  can  be 
used  as  toning  fluid  upon  tanned  leather,  or  upon  leather  dyed 
with  color  containing  tannin  when  very  dark,  nearly  black 
tones  are  to  be  produced.  Moreover,  it  may  here  be  re- 
marked that  every  color,  no  matter  with  what  toning  fluid  it 
may  be  treated,  becomes  darker  in  consequence  of  such  treat- 
ment. Alum  solution  when  used  as  a  toning  fluid,  however, 
is  to  a  certain  extent  an  exception,  since  it  serves  the  purpose 
of  fixing  upon  the  surface  of  the  leather  any  non-fixed  color- 
ing matter  present.  Regarding  the  toning  fluids  in  general,  it 
may  be  remarked  that  great  care  must  be  observed  in  using 
them  in  their  more  concentrated  state,  otherwise  the  resulting 
tones  will  be  too  dark. 

Toning  fluids  may  be  prepared  in  the  following  proportions : 


No.  I.    Alum  , 
Water 


2-5 

IOO. 


58° 


THE  MANUFACTURE  OF  LEATHER. 


No.  2.    Alum   5. 

Water   100. 

No.  1.    Copperas   1. 

Water   100. 

No.  2.    Copperas   1. 

Water   100. 

No.  3.    Copperas    3. 

Water   100. 

No.  4.    Copperas   4. 

Water  .'   100. 

Remarks :  No.  3  serves  for  deep  gray  and  black-blue,  No.  4 
exclusively  for  black. 

No.  1.    Sulphate  of  copper   I. 

Water   100. 

No.  2.    Sulphate  of  copper   2. 

Water   100. 

No.  3.    Sulphate  of  copper   3. 

Water   100. 

No.  1.    Sulphate  of  zinc   2.5 

Water   100. 

No.  1.    Potassium  chromate   0.5 

Water   100. 


Remarks  :  The  latter  fluid  only  for  logwood  and  black. 

THE  COLOR  MIXTURES. 

On  account  of  the  variations  in  the  chemical  constitution  of 
the  different  kinds  of  leather,  the  color-mixtures  used  in  dyeing 
must  be  different  for  every  variety  of  leather,  and  we  will  here 
give  the  most  important  directions  regarding  the  respective 
proportions  for  the  different  kinds  of  leather. 

Genuine  Russia  Leather. — This  leather  is  generally  dyed  only 
two  colors,  either  black  or  red. 

Black  is  produced  by  mordanting  with  alum  and  copperas, 
and  subsequent  treatment  with  logwood  decoction. 

Red  is  produced  by  mordanting  with  alum  and  subsequent 
application  of  decoction  of  sanders  wood.  The  result  of  this 
treatment  is  a  quite  pure  bright  red.  If  the  color  is  to  have  a 
brown  tinge,  decoction  of  logwood  may  to  a  limited  extent  be 
used,  together  with  decoction  of  sanders  wood. 


THE  DYEING  OF  LEATHER. 


Russia  leather  for  articles  of  luxury  may  be  dyed  every  de- 
sired color  with  aniline  colors,  with  the  exception  of  the  deli- 
cate and  pale  tones,  which  demand  the  presence  of  a  white  basis. 

Morocco  Leather. — The  following  dye-stuffs  are  used  for  the 
old  style  of  sumac  tanned  morocco  leather — the  colors  would 
not  answer  for  the  modern  kid  leather  unless  it  be  first  mord- 
anted with  a  warm  solution  of  sumac  : 

For  yellow:  Barberries,  fustic,  or  French  berries  (berries  of 
Avignon). 

For  orange :  Equal  parts  of  decoction  of  brazil  wood  and 
fustic,  and  for  toning  after  the  first  dyeing  with  decoction  of 
barberries  in  larger  or  smaller  quantities  of  alum. 

For  red  :  Decoction  of  brazil  wood  only. 

For  green  :  Yellow,  according  to  one  of  the  previously  given 
methods,  and  upon  this  blue  according  to  the  following  process  : 

For  blue:  Indigo  (soluble),  soluble  Berlin  blue,  or  Berlin 
blue  from  yellow  prussiate  of  potash  and  ferric  oxide. 

For  brown  :  Logwood  and  toning  with  copperas  and  alum. 

For  black  :  Logwood,  a  small  quantity  of  fustic  and  copperas. 

Cordovan  Leather. — The  principal  colors  of  this  leather  as 
found  in  commerce  are  yellow,  red  and  black.  It  is  dyed  as 
follows : 

Yellow:  With  French  berries  and  alum. 
Red  :  With  kermis  grains  and  alum. 
Black :  With  logwood  and  copperas. 

Chamois  Leather. — This  leather,  when  bleached  with  sul- 
phurous acid,  is  dyed  like  tanned  leather.  If  not  bleached  with 
sulphurous  acid  it  is  simply  colored  rather  in  a  mechanical 
than  chemical  way,  for  instance,  by  rubbing  in  whiting,  ochre, 
as  well  as  chrome  yellow  and  reddle.  For  black,  decoction  of 
gall-nuts  is  used  and  afterwards  acetate  of  iron. 

Tawed  Leather. — On  account  of  its  white  color  and  its  con- 
tent of  alum,  which  does  not  exert  an  injurious  effect  upon  the 
most  delicate  shade,  this  leather  can  be  dyed  almost  any  color. 
The  dyeing  of  tawed  leather  has  been  greatly  simplified  by  the 
extraordinary  beauty  of  the  aniline  colors  and  the  facility  with 


582 


THE  MANUFACTURE  OF  LEATHER. 


which  they  adhere  to  the  leather,  it  being  only  necessary  to 
prepare  a  solution  of  proper  concentration  of  the  dye-stuff. 
However,  for  certain  undecided  colors,  especially  for  the 
various  grays,  browns  and  brown-greens,  the  aniline  colors  are 
not  very  suitable,  although  the  respective  tones  may  be  pro- 
duced with  them.  We  will,  therefore,  briefly  mention  the  dye- 
stuffs  required  for  dyeing  tawed  leather  according  to  the  old 
method. 

For  yellow :  Barberries,  fustic,  chrome  yellow,  for  delicate 
yellow  also  weld.  However,  at  present,  picric  acid  is  most 
frequently  used,  and  with  it,  according  to  the  concentration  of 
the  solution,  every  shade  of  yellow  can  be  produced. 

For  red :  For  dark  red,  brazil  wood  in  concentrated  form 
and  alum  toning  fluid  ;  for  lighter  shades  to  delicate,  rosewood, 
dilute  decoction  of  brazil  wood,  as  well  as  cochineal.  At 
present  a  fine  quality  of  fuchsin  is  most  frequently  used  for 
delicate  red. 

For  green :  Yellow  as  above,  and  blue.  For  the  pure  color 
alone  aniline  green  is  now  frequently  used  and  besides  for 
broken  green,  logwood.  Pale  green  (water  green,  Nile  green) 
is  produced  with  soluble  indigo  and  picric  acid. 

For  blue  :  Soluble  indigo,  Berlin  blue  from  yellow  prussiate 
of  potash  and  copperas. 

For  violet:  Red  as  above  and  soluble  indigo;  or  directly 
methyl  violet  or  for  broken  violet  fuchsin  and  logwood. 

For  brown :  Logwood,  Brazil  wood  and  fustic  in  various 
mixtures. 

For  gray :  The  same  dyestuffs  as  for  browns,  only  in  differ- 
ent proportions. 

For  black:  Logwood  (with  or  without  Brazil  wood)  and 
potassium  chromate  or  copperas  (also  acetate  of  iron). 

For  all  the  dye-stuffs  mentioned  above  the  aniline  colors  offer 
the  best  substitute.  It  is,  however,  by  no  means  necessary  to 
provide  the  numerous  preparations  which  are  found  in  com- 
merce under  all  kinds  of  names,  and  generally  are  nothing  else 
but  a  well-known  color  under  a  new  name. 


THE  DYEING  OF  LEATHER. 


583 


From  the  dye-stuffs  above  mentioned  all  the  colors  required, 
especially  in  dyeing  kid,  can  be  readily  compounded.  How- 
ever, in  buying  the  dye-stuffs  care  should  be  taken  to  select  the 
finest  qualities,  even  if  comparatively  dear,  since  actually  pure 
tones  can  only  be  obtained  with  them.  The  correctness  of  this 
advice  can  be  readily  proved.  There  occurs  in  commerce,  for 
instance,  a  fuchsin  or  an  aniline  violet  which  is  much  cheaper 
than  other  preparations  of  the  same  kind,  and  in  a  solid  state 
as  well  as  in  concentrated  solution  shows  no  apparent  differ- 
ences from  the  better  qualities ;  both  the  cheap  as  well  as  the 
more  expensive  dye-stuff"  yielding  beautiful  red  or  violet  solu- 
tions. 

In  making,  however,  a  dyeing  test  with  both  preparations, 
the  difference  becomes  immediately  apparent,  the  more  ex- 
pensive fuchsin  yielding  a  pure  fiery  red,  while  with  the  cheaper 
article  it  is  impossible  to  obtain  the  same  result,  the  tones 
always  appearing  veiled  with  yellow  or  brown  admixtures. 
The  two  kinds  of  violet  behave  the  same  way  in  dyeing.  The 
cause  of  this  phenomenon  is  found  in  the  fact  that  the  cheap 
preparations  have  not  been  freed  by  recrystallization  from  ad- 
mixed products  which  have  been  formed,  besides  the  actual 
coloring  matter,  in  the  preparation  of  the  fuchsin  or  violet,  and 
these  products  possessing  also  the  power  oi  dyeing  exert  an 
injurious  effect  upon  the  pure  color.  With  the  extraordinary 
dyeing  power  of  the  aniline  colors  it  would  be  false  economy 
to  buy  the  cheaper  qualities,  since  it  is  impossible  to  obtain 
with  them  pure  colors. 

The  most  important  dyes  of  the  group  of  the  aniline  colors 
are  picric  acid,  fuchsin,  water-soluble  blue,  methyl  violet  and 
iodine  green. 

For  pure  colors  without  toning,  the  above  mentioned  colors 
are  used  by  themselves,  and  by  suitably  diluting  the  solutions 
the  strongest  colors  may  be  produced,  as  well  as  those  which, 
like  a  breath,  simply  modified  the  white  basis  color  of  the 
leather  to  yellowish,  reddish,  bluish,  etc. 

For  colors  which  are  formed  by  mixing  two  coloring  matters, 


* 


5  84 


THE  MANUFACTURE  OF  LEATHER. 


mixtures  of  the  solutions  of  these  coloring  matters  can  be 
directly  employed.  Thus  for  orange,  picric  acid  and  fuchsin 
are  used,  for  green,  picric  acid  and  soluble  blue,  for  violet, 
fuchsin  and  soluble  blue,  and  by  allowing  one  or  the  other 
coloring  matter  to  predominate,  various  shades  of  the  respect- 
ive mixed  color  may  be  obtained. 

Since  the  blended  colors,  brown  and  gray,  may  also  be  com- 
pounded from  the  three  primary  colors,  yellow,  red  and  blue- 
and  the  latter  in  their  greatest  purity  are  represented  among 
the  aniline  colors  by  picric  acid,  fuchsin  and  water-soluble  blue, 
the  blended  may  also  be  prepared  by  mixing  these  three  primary 
colors.  With  the  assistance  of  aniline  salts,  pure  black  may 
also  be  produced,  and  hence  it  maybe  said  that  in  an  establish- 
ment in  which  aniline  colors  are  exclusively  used,  all  tones  of 
colors  can  be  obtained  which  otherwise  are  produced  with  the 
aid  of  the  various  coloring  matters  of  vegetable  and  animal 
origin. 

In  many  establishments  for  dyeing  leather  it  is  customary  to 
use  aniline  colors  besides  coloring  matters  obtained  from  woods 
or  other  vegetable  substances,  the  aniline  colors  for  economical 
reasons  being,  as  a  rule,  employed  only  for  brightening  the 
colors.  By  taking,  however,  into  consideration  the  cost  of  the 
coloring  matters  and  the  extra  labor  involved,  it  will  readily  be 
seen  that  dyeing  with  aniline  colors  is  not  more  expensive,  so 
that  it  may  also  be  recommended  from  this  point  of  view. 

PREPARATION  OF  THE  LEATHER  FOR  DYEING. 

The  leather  to  be  dyed  must  be  carefully  inspected  and 
sorted,  since  every  kind  of  leather  cannot  in  the  same  manner 
be  used  for  dyeing.  Leather  which  is  not  of  uniform  density 
does  not  take  the  dye  in  a  uniform  manner,  and  no  matter  how 
carefully  the  work  may  have  been  done,  the  product  will  turn 
out  spotted  or  cloudy.  For  sorting  the  leather  to  be  dyed, 
practical  experience  is  of  the  utmost  importance.  The  work- 
men entrusted  with  the  work  must  know,  without  much  hesita- 
tion, by  the  feel  and  appearance  of  the  skins,  what  is  to  be  done 
with  them  as  regards  dyeing. 


THE  DYEING  OF  LEATHER. 


585 


SORTING. 

The  principal  point  to  be  observed  in  sorting  morocco  and 
cordovan  leather  for  dyeing  is  uniformity  and  softness  of  the 
skins.  Very  light  colors  are  not  applied  to  these  varieties  of 
leather.  In  sorting  chamois  leather  which  is  to  be  dyed,  the 
skins  distinguished  by  special  uniformity  are  also  selected. 

The  most  difficult  task  is  the  sorting  of  tawed  leather,  espec- 
ially the  small  skins  intended  for  glace  leather.  It  is,  for  in- 
stance, well  known  that  gloves  the  color  of  which  shows  very 
slight  defects  are  thrown  out  as  seconds,  and  the  dyer  who  does 
not  desire  to  produce  a  large  quantity  of  them  must  learn  to 
avoid  even  very  small  blemishes. 

Leather  which  when  dyed  delicate  colors  would  give  many 
seconds,  may,  however,  be  utilized  for  dark  colors,  but  the 
latter  must  be  the  darker  the  more  pronounced  the  defects  are. 
In  sorting  it  is,  therefore,  best  to  separate  the  skins  into  several 
classes  and  dye  accordingly. 

The  first  class  might  comprise  the  leather  which  is  not  to  be 
dyed,  but  intended  to  be  worked  into  white  ball-gloves.  Beside 
a  very  fine  and  smooth  grain,  this  leather  must  be  distinguished 
by  special  softness  and  pliability.  Such  skins  are  simply 
bleached,  if  necessary  blued,  and  mechanically  worked  to  im- 
part to  them  uniform  thickness  and  luster. 

The  second  class  might  embrace  the  leather  which  besides- 
possessing  softness  and  pliability,  is  perfectly  free  from  blem- 
ishes. Such  leather  is  used  for  the  most  delicate  colors,  such 
as  straw  yellow,  pearl  gray,  pale  brown,  as  well  as  for  blue  with 
aniline  colors. 

The  third  class  might  comprise  the  leather  which  shows  such 
small  defects  as  might  be  very  prominent  with  light  colors,  but 
disappear  with  darker  colors.  Such  skins  are  dyed  dark  gray, 
dark  brown,  but  especially  blended  colors,  such  as  date  colorr 
olive  green,  etc. 

The  fourth  class  might  include  leather  with  more  serious  de- 
fects than  the  foregoing,  and  the  grain  side  of  which  is  not 


586 


THE  MANUFACTURE  OF  LEATHER. 


quite  smooth,  but  which  nevertheless  possesses  softness  and 
pliability.    Such  leather  is,  as  a  rule,  dyed  black. 

Finally,  the  fifth  class  might  embrace  the  leather  which 
shows  grave  defects  and  an  uneven  grain,  less  pliability,  and  a 
non-uniform  thickness.  Such  leather  is  always  dyed  black.  It 
is  seldom  worked  into  gloves,  but  chiefly  utilized  as  fine  shoe 
leather. 

WASHING  THE  SKINS. 

In  the  subsequent  operation  to  which  the  sorted  skins  are 
subjected,  it  is  advisable  to  handle  at  the  same  time  only  skins 
belonging  to  the  same  class,  since  in  consequence  of  their 
uniformity  they  behave,  as  will  be  readily  understood,  in  the 
same  manner  throughout  these  operations,  whereby  the  work  is 
essentially  facilitated. 

The  first  operation  which  actually  belongs  to  the  preparation 
of  the  skins  is  washing.  The  chief  object  of  washing  tanned 
skins  is  to  remove  mechanically  adhering  dust,  to  dissolve  an 
excess  of  tannin  which  is  not  firmly  fixed  upon  the  fiber,  and 
uniformly  to  moisten  the  skins  so  that  in  the  subsequent 
mordanting  and  dyeing,  the  mordant  as  well  as  the  dyeing 
liquid  can  penetrate  to  a  certain  depth  into  the  leather,  thus 
making  the  color  more  solid  and  more  durable.  The  skins  to 
be  cleansed  are  first  spread  smoothly  on  a  table,  which  should 
be  perfectly  level,  and  treated  with  wet  brushes.  They  are 
then  placed  in  water  of  68°  to  77°  F.,  and  allowed  to  remain  a 
few  hours  until  the  water  has  acquired  a  brownish  color  from 
the  dissolved  substances.  The  skins  are  then  transferred  to 
clean  water,  in  which  they  remain  until  they  have  acquired  the 
proper  degree  of  softness.  They  are  then  taken  out  and,  when 
quite  dry  on  the  surface,  subjected  to  the  operations  of  mor- 
danting and  dyeing. 

Much  greater  care  has  to  be  exercised  in  washing  tawed 
leather  which  is  to  be  worked  for  glace  leather.  Small  particles 
of  the  alum  and  of  the  nourishing  paste  used  in  tawing  adhere 
to  the  surface  of  the  skins  and  are  also  imbedded  in  the  pores. 


THE  DYEING  OF  LEATHER. 


587 


We  know  that  alum  possesses  the  property  of  fixing  coloring 
matters.  Now  if  some  portions  of  the  skin  have  retained  more 
alum  than  others,  more  coloring  matter  will  be  precipitated 
there  and  the  dyeing  will  not  turn  out  uniform  all  over.  By 
examining  with  the  microscope  colored  leather  not  sufficiently 
washed  previous  to  dyeing,  a  number  of  darker  spots  due  to  a 
heavier  fixation  of  coloring  matter  on  the  places  richer  in  alum 
will  be  plainly  seen. 

According  to  the  opinion  of  many  dyers  the  object  of  wash- 
ing is  to  remove  as  much  alum  as  possible  from  the  leather. 
However,  in  our  opinion  this  idea  is  not  correct,  since  the  un- 
avoidable consequence  of  the  partial  extraction  of  tawing 
matter  would  be  that  the  outer  portions  of  the  leather  thus 
treated  would,  in  drying,  shrink  in  a  different  manner  from  the 
interior  portions  from  which  the  tawing  matter  has  not  been 
withdrawn,  and  the  leather  would  not  acquire  the  beautiful 
luster  of  leather  not  subjected  to  this  treatment.  It  may  here 
be  remarked  that  this  error  can  never  be  entirely  corrected  by 
the  subsequent  treatment  with  nourishing  paste.  Hence  the 
leather  should  only  be  washed  sufficiently  to  remove  any  excess 
of  alum.  It  can  then  be  readily  and  uniformly  dyed  and  with- 
out trouble  be  converted  into  actual  glace  leather,  i.  e.,  leather 
with  great  luster. 

For  washing  lukewarm  water  is  used,  a  number  of  skins  to 
be  dyed — 30  to  50  dozen — being  generally  treated  at  one  time. 
To  assure  uniform  moistening  of  all  the  skins  it  is  best  to  use 
a  large  vat.  One  skin  after  the  other  is  then  immersed  in  the 
water,  moved  to  and  fro,  and  spread  out  smoothly  on  the 
bottom  of  the  vat. 

For  the  uniform  and  vigorous  washing  of  the  skins  it  is 
necessary  to  subject  them  to  a  certain  mechanical  pressure, 
and  it  is  generally  done  by  workmen  treading  them  with  their 
bare  feet.  It  will  be  readily  understood  that  the  process  is 
quite  primitive  and,  as  manual  labor  has  to  be  used,  also  quite 
expensive.  However,  notwithstanding  these  drawbacks,  which 
are  perfectly  understood  by  most  dyers,  many  of  them  assert 


588 


THE  MANUFACTURE  OF  LEATHER. 


that  the  treading  of  the  skins  cannot  be  replaced  by  any  other 
method  of  manipulation,  and  that  only  in  this  manner  can  the 
skins  be  prepared  for  uniform  dyeing. 

THE  WASHING  MACHINE. 

The  above-mentioned  assertion  is,  however,  incorrect,  since 
the  work  of  washing  and  proper  manipulation  may  be  executed 
with  the  assistance  of  mechanical  appliances,  the  arrangement 
shown  in  Fig.  144  being  well  adapted  for  the  purpose.  The 
skins  to  be  washed  are  hung  together  by  twine  drawn  through 
holes  in  the  foot  pieces.  However,  since  fresh  twine  would  be 
required  for  each  operation  it  has  been  endeavored  to  substi- 
tute another  material  for  it,  quite  thin,  well-tinned  iron  wire, 
bent  to  a  hook  of  the  form  of  an  S,  being  found  the  most  suita- 
ble for  the  purpose.    It  is  absolutely  necessary  that  these 


Fig.  144. 


hooks  should  be  thoroughly  tinned,  since  if  the  skin  comes  in 
contact  with  the  iron  itself,  that  portion  would,  in  the  subse- 
quent dyeing,  turn  out  spotted.  Hence  the  hooks  must  be 
closely  inspected,  and  any  one  which  shows  the  bright  iron 
through  the  tin  coating  immediately  removed. 

The  apparatus  consists  of  two  vats  (A' and  Kr).  Into  one 
of  these  vats  the  skins  are  brought  as  follows :  The  first  skin  is 
laid,  flesh  side  down,  and  upon  it,  connected  with  it  by  hooks, 


THE  DYEING  OF  LEATHER. 


589 


is  placed  the  second  skin,  grain  side  down  ;  upon  this  is  laid 
the  third  skin,  flesh  side  down,  and  upon  the  latter  the  fourth 
skin,  grain  side  down,  and  so  on.  Above  the  vat  {K)  are 
fixed  a  few  guide  rolls  and  alongside  of  it  are  standards  carry- 
ing two  rolls  (B  and  B,).  These  rolls  may  be  revolved  in 
every  direction,  and  their  peripheries  are  furnished  with  bristles 
so  that  they  actually  form  cylindrical  brushes.  In  order  to 
press  the  two  rolls  with  a  certain  force  against  each  other,  a 
block  of  wood  (H)  is  placed  over  each  end  of  the  axle  of  the 
upper  roll.  The  blocks  of  wood  are  connected  by  a  cross 
piece  which  carries  a  wooden  box  filled  to  a  suitable  depth 
with  sand,  whereby  a  moderate  pressure  is  exerted.  Along- 
side the  standards  carrying  the  brush  rolls  (B  and  B,)  are 
similar  standards  in  which  rest  two  wooden  cylinders  (6"and  C,) 
of  equal  size,  the  surfaces  of  which  are  covered  with  vulcanized 
rubber.  These  rolls  can  be  pressed  together  by  means  of  a 
screw.  To  one  of  the  rolls  is  fixed  a  crank  as  well  as  a  pulley, 
the  latter  being  connected  by  means  of  a  belt  with  a  pulley  on 
By  so  that  both  rolls  must  move  simultaneously.  The  vat  (A'y) 
is  also  provided  with  guide  rolls  arranged  in  the  same  manner 
as  those  on  K . 

When  the  skins  have  in  the  above  described  manner  been 
placed  in  the  vat,  sufficient  water  to  cover  them  is  admitted,  and 
they  are  then  allowed  to  stand  quietly  for  one  hour.  To  avoid 
the  formation  of  air-bubbles  between  the  separate  skins  it  is 
recommended  to  admit  the  water  through  a  rubber  hose  while 
arranging  the  skins  in  the  vat,  and  to  regulate  the  flow  of  water 
so  that  the  skins  placed  last  are  covered  about  one-half  inch 
deep  with  water.  If  the  skins  have  been  properly  brought  into 
the  vat  they  will  be  uniformly  moistened  in  about  one  hour, 
and  the  mechanical  manipulation  may  be  proceeded  with  as 
follows :  Lift  the  uppermost  skin  from  the  vat,  push  it  between 
the  brush-rolls  (B  and  B,)  and  set  the  crank  on  the  roll  (C) 
in  motion.  The  skin  as  it  emerges  from  between  B  and  B,  is 
pushed  with  the  hand  between  the  rolls  (C  and  C,).  By 
the  brush-rolls  the  entire  surface  of  the  wet  skins  is  uniformly 


59Q 


THE  MANUFACTURE  OF  LEATHER. 


brushed,  and  adhering  particles  of  nourishing  paste  and  of 
alum  are  removed.  Where  plenty  of  water  can  be  had  it  may 
be  recommended  to  arrange  pipes  perforated  with  small  holes 
below  the  lower,  and  above  the  upper  roll,  and  squirt  water 
through  them  upon  the  skins.  While  such  arrangement  is  not 
absolutely  necessary,  it  facilitates  the  work. 

As  will  be  seen  from  the  arrangement  of  the  apparatus,  the 
skins  which  have  been  manipulated  between  B  and  B,  must 
pass  between  C  and  C,,  and  are  there  subjected  to  a  uniform 
and  quite  strong  pressure,  so  that  not  only  the  water  adhering 
to  the  surface,  but  also  a  portion  of  the  water  absorbed  by  them 
is  withdrawn. 

The  skins  having  thus  been  quite  vigorously  expressed  now 
reach  the  vat  (A",).  The  progress  of  the  work  should,  how- 
ever, be  so  regulated  that  the  workman  who  has  charge  of  the 
vat  (A,)  has  sufficient  time  to  arrange  the  skins  in  it  in  the 
same  manner  as  they  were  originally  arranged  in  K,  water 
being  admitted  at  the  same  time. 

In  placing  the  skins  in  the  vat  (A'/),  those  which  were  on 
top  in  K  come  now  on  the  bottom,  which  is  of  great  advantage 
for  the  uniformity  of  the  work,  since  the  skins  on  the  bottom 
are  evidently  subjected  to  the  pressure  of  a  higher  volume  of 
fluid  than  those  on  top,  and  are  consequently  soaked  through 
in  a  much  shorter  time.  When  all  the  skins  have  in  this  man- 
ner been  brought  into  the  vat  (A'7),  they  are  allowed  to  re- 
main in  it  for  one  hour.  The  belt  is  then  detached  from  the 
two  pulleys,  and  the  contrivance  carrying  the  brush-rolls  (B 
and  B,)  is  so  placed  that  it  stands  between  the  rubber-faced 
rolls  (Cand  C,)  and  the  vat  (A',).  The  belt  is  then  thrown 
upon  the  pulleys,  and  by  revolving  the  rolls  the  skins  are  con- 
veyed back  to  the  vat  (A'). 

If  it  is  desired  to  manipulate  many  skins  at  one  time,  the  vats 
{K  and  Kf)  would  have  to  be  quite  deep,  which  is,  however, 
inconvenient  for  arranging  the  skins.  It  is  therefore  preferable 
to  give  the  vessels  the  shape  of  a  trough  rather  than  that  of  a 
vat,  so  that  four  to  six  skins  may  be  placed  alongside  one 
another. 


THE  DYEING  OF  LEATHER. 


591 


Every  time  after  the  skins  have  been  lifted  from  either  of  the 
vats,  the  water  must,  of  course,  be  discharged.  In  dyeing  es- 
tablishments connected  with  a  tannery  the  first  wash  water, 
which  contains  a  certain  quantity  of  alum  in  solution,  may  be 
used  for  dissolving  the  alum  used  in  tawing. 

One  of  the  most  important  questions  which  arises  is,  how 
long  must  washing  be  continued?  To  answer  this  question 
properly  it  is  necessary  to  enter  somewhat  into  the  considera- 
tion of  the  condition  of  leather. 

According  to  the  opinion  prevailing  at  present  regarding 
the  nature  of  the  tanning  process,  tanning  is  effected  by  the 
tanning  agent — in  this  case  alum — enveloping  the  fibers  of 
which  the  skin-tissue  consists  and  preventing  the  leather  from 
becoming  hard  in  drying,  the  nourishing  paste  co-operating 
thereby  in  the  same  manner.  Hence  the  alum  is  deposited 
upon  the  fibers  of  the  skin  simply  by  surface-attraction,  but  if 
tawed  leather  be  brought  in  contact  with  water  the  dissolving 
power  of  the  latter  overcomes  the  surface-attraction,  and  alum 
is  removed  from  the  surface  of  the  fibers.  Hence  if  a  piece  of 
tawed  leather  is  allowed  for  some  time  to  remain  in  water 
which  is  frequently  changed,  it  can  be  completely  freed  from 
tanning  material;  i.  e.,  reconverted  into  raw  skin.  By  drying, 
such  leather  shrivels  up  to  a  hard,  tough  mass  similar  to  raw 
skin,  and  if  kept  constantly  moist,  becomes  finally  putrid. 

Of  course,  washing  will  never  be  carried  to  such  an  extent 
as  to  free  the  leather  completely  from  tanning  material.  It 
must,  however,  be  taken  into  consideration,  that  if  washing  be 
continued  even  somewhat  too  long,  the  surface  may  be  partially 
divested  of  tanning  material ;  and  this  has  the  double  disad- 
vantage that,  in  order  to  obtain  leather  of  a  proper  degree  of 
softness,  an  exceedingly  large  quantity  of  yolk  of  egg  has  later 
on  to  be  used  as  nourishment,  whereby  the  expense  of  produc- 
tion is  unnecessarily  increased,  and  besides  a  special  alum- 
mordant  has  to  be  applied  previous  to  actual  dyeing,  as  other- 
wise there  would  not  be  sufficient  alum  upon  the  surface  of  the 
leather  to  fix  the  coloring  matter.    The  latter  difficulty  is  of 


592 


THE  MANUFACTURE  OF  LEATHER. 


less  importance  in  dyeing  with  aniline  colors,  they  being  sub- 
stantive upon  animal  fibers ;  i.  e.,  they  combine  with  them 
without  previous  mordanting,  though  they  also  adhere  better 
when  alum-mordant  is  present.  Besides,  in  dyeing  very  deli- 
cate colors,  for  instance,  straw-yellow  or  pearl-gray,  the  dyeing 
liquor  has  to  be  used  in  a  very  dilute  state,  and  the  small  quan- 
tity of  coloring  matter  is  partially  fixed  by  the  alum  still 
present  in  the  leather  and  partially  by  the  toning  fluid  used 
after  the  application  of  the  dye.  Hence,  leather  intended  for 
very  light  colors  may  be  washed  somewhat  longer  than  leather 
to  be  dyed  dark,  though  regarding  the  latter  a  factor  to  be 
immediately  discussed  has  to  be  taken  into  consideration ; 
namely,  if  leather  is  to  be  dyed  by  the  dipping  process ;  i.  c, 
by  dipping  it  in  the  dyeing  liquor,  it  will,  of  course,  be  dyed 
upon  both  sides.  This,  however,  is  not  desirable,  since  leather 
to  be  used  for  gloves,  especially  if  dyed  somewhat  darker 
colors,  would  stain  the  skin  and  hence  would  not  be  available 
for  that  purpose.  Hence,  leather  to  be  dyed  by  dipping  should 
be  washed  to  such  an  extent  that  the  lower  side  fixes  but  a 
very  small  quantity  of  coloring  matter,  not  sufficient  to  stain 
the  hand,  even  if  the  upper  side  is  dyed  very  dark. 

From  the  explanations  given  above,  the  following  rules  in 
reference  to  washing  leather  may  be  deduced : 

1.  Leather  to  be  dyed  by  the  application  of  aniline  colors 
should  only  be  washed  sufficiently  to  free  the  side  to  be  dyed 
from  mechanically  adhering  particles  of  nourishing  paste  and 
small  crystals  of  alum. 

2.  Leather  to  be  dyed  by  dipping  should  be  washed  until 
the  lower  side  contains  but  very  little  alum,  so  that  it  will  take 
only  a  small  amount  of  coloring  matter. 

3.  Leather  to  be  dyed  very  delicate  colors,  either  by  dipping 
or  brushing,  may  be  washed  longer. 

4.  The  longer  the  leather  has  been  washed,  the  more 
nourishing  paste  must  be  given  in  order  to  render  it  again 
sufficiently  pliant. 

It  is  scarcely  necessary  to  give  a  fixed  time  required  for 


THE  DYEING  OF  LEATHER. 


593 


washing,  since  this  depends  largely  on  the  nature  of  the  skins 
to  be  washed  and  on  the  temperature  of  the  wash  water.  The 
denser  the  leather  is  and  the  colder  the  water  used,  the  longer 
the  washing  will  have  to  be  continued,  since  under  these  condi- 
tions it  takes  more  time  to  moisten  the  fibers  to  a  certain  depth 
and  to  dissolve  a  corresponding  quantity  of  alum.  Hence  for 
washing  denser  and  stouter  leather  it  is  best  to  use  somewhat 
warmer  water,  to  shorten  the  time  required  for  the  operation. 
On  the  other  hand,  for  thin,  spongy  skins  water  of  the  ordinary 
temperature  should  be  used  and  great  care  observed  in  the 
operation.  As  previously  stated  the  time  required  for  washing 
cannot  be  given,  it  depending  entirely  on  practical  experience. 

The  dyer  must  ascertain  by  tests,  which  he  makes  with  the 
skins,  how  long  washing  may  suitably  be  continued.  Such  ex- 
periments are  worth  far  more  than  working  according  to  a 
fixed  time,  which  can  be  correct  only  in  a  certain  case. 

QUALITY  OF  THE  WATER. 

A  few  remarks  may  here  be  made  regarding  the  quality  of 
the  water  to  be  used  in  washing  and  dyeing  leather.  The 
water  must  of  course  be  perfectly  clear.  If  after  standing  for 
some  hours  in  a  large  bottle  it  deposits  only  a  trace  of  solid 
substance,  it  is  unfit  for  our  purposes  and  has  to  be  subjected 
to  filtration,  which  will  be  referred  to  later  on. 

The  chemical  constitution  of  the  water  is  also  of  considerable 
importance  to  the  dyer.  Many  well  waters,  as  is  well  known, 
are  very  hard,  i.  c,  they  contain  large  quantities  of  calcium  car- 
bonate in  solution,  which  causes  the  separation  of  aluminium 
hydrate  from  the  alum;  and  in  case  somewhat  more  alum  be 
present  on  one  portion  of  the  leather  than  on  another,  more 
aluminium  hydrate  will  remain  behind,  whereby  that  portion 
becomes  darker,  and  the  leather,  consequently,  spotted. 

Such  water  can  scarcely  be  used  in  washing  and  dyeing,  but 
where  no  other  can  be  had,  it  should  be  boiled  before  use,  or 
what  is  more  suitable  for  the  large  quantities  required,  com- 
pounded with  soda  solution.  The  soda  renders  the  calcium 
38 


594 


THE  MANUFACTURE  OF  LEATHER. 


carbonate  insoluble  and  the  water  becomes  turbid  in  conse- 
quence. To  avoid  an  excess  of  soda  it  is  best  to  determine 
once  for  all  the  quantity  required  to  separate  all  the  calcium 
carbonate  from  say  fifty  gallons  of  water,  and  to  use  a  propor- 
tional quantity.  Bring  the  water  into  a  large  vat,  stir  in  the 
soda  solution,  allow  to  settle  and  then  draw  off  the  clear  water. 

Borax  should  be  used  in  preference  to  soda  for  softening  the 
water,  as  it  is  one  of  the  gentlest  of  the  alkalies  and  is  at  the 
same  time  a  fine  mordant.  One-half  pound  of  borax  is  gener- 
ally used  to  one  hundred  gallons  of  water.  The  borax  is  dis- 
solved in  boiling  water  and  added  under  vigorous  stirring.  If 
the  water  is  very  hard  a  little  more  borax  will  be  required. 

For  filtering  turbid  water  Forster's  sandstone  filter  shown  in 
Fig.  145,  is  very  suitable.    It  consists  of  a  hollow  sandstone 


cylinder  (C)  having  a  clear  diameter  of  4  inches  and  a  length 
of  8  inches.  The  cylinder  is  cemented  in  a  cast  iron  lid,  the 
latter  sitting  upon  a  sheet  iron  jacket  inserted  below  in  an  iron 
foot.  The  water  to  be  filtered  passes  under  a  certain  pressure 
from  the  lower  portion  of  the  apparatus,  at  W,  into  the  jacket 
(M),  permeates  through  the  pores  of  the  sandstone  cylinder 
(6")  and  runs  off  through  the  lid  on  top.  When  the  pores  of 
the  cylinder  are  clogged  up  by  solid  substances  to  such  an  ex- 


Fig.  145. 


THE  DYEING  OF  LEATHER. 


595 


tent  that  filtration  proceeds  slowly,  the  cylinder  is  replaced  by 
a  new  one,  and  cleansed  by  turning  or  grinding  the  surface. 

If  the  water  contains  a  considerable  quantity  of  organic  sub- 
stances, the  production  of  certain  delicate  colors  with  it  is  next 
to  impossible,  and  in  order  to  render  it  fit  for  use  it  has  to  be 
filtered  through  so-called  plastic  coal.  The  latter  consists  of 
animal  charcoal  dust  or  meal  which  is  made  into  a  paste  with 
glue  water.  This  paste  is  given  definite  shapes  by  moulding 
and  the  cementing  agent  destroyed  by  heating.  The  plastic 
coal  generally  has  the  form  of  a  low  hollow  cylinder,  and  a 
number  of  such  cylinders,  for  instance  nine,  sixteen,  etc.,  are 
combined  to  a  filtering  battery,  as  shown  in  Fig.  146. 

Fig.  146. 


PI 

11  

Each  cylinder  is  about  8  inches  in  diameter  and  4  inches 
high.  The  cylinders  are  connected  with  each  other  by  short 
pieces  of  iron  pipe.  The  lowest  cylinder,  with  its  pipe,  is 
screwed  to  the  false  bottom  of  the  vat  and  is  connected  with 
the  uppermost  by  means  of  a  rubber  hose,  which  projects 
above  the  level  of  the  water.  With  a  filter  of  this  construction, 
not  only  turbid  water  can  be  filtered  clear,  but  it  is  also  freed 
from  organic  substances  in  solution,  the  animal  charcoal  pos- 
sessing the  property  of  absorbing  and  retaining  such  substances. 


NOURISHING. 

No  matter  how  much  care  may  have  been  exercised  in  wash- 


596 


THE  MANUFACTURE  OF  LEATHER. 


ing,  the  leather  will  always  be  somewhat  hard  if  its  original 
pliancy  is  not  restored  by  the  so-called  nourishment. 

For  the  nourishment  of  fine  glace  leather,  yolk  of  eggs  is, 
as  a  rule,  used,  the  effect  of  the  fat,  called  egg-oil,  contained  in 
it,  being  such  as  to  keep  the  leather  pliable  after  drying. 
Chemically,  yolk  of  egg  consists  of  vitellin,  a  peculiar  body  be- 
longing to  the  group  of  albumens,  further  fat  and  fat-like  bodies 
( cholesterin,  lecithine)  and  a  special  yellow  coloring  matter — 
lulein — and  potassium  salts.  For  our  purposes,  however,  the 
effective  body  of  the  yolk  of  egg  is  the  fat,  which  is  in  a  state 
of  emulsion,  i.  c,  in  the  form  of  very  small  drops  suspended  in 
the  fluid.  Since  alkalies  also  possess  the  property  of  convert- 
ing fat  into  an  emulsion,  it  is  recommended  to  use,  besides  yolk 
of  egg,  very  small  quantities  of  soda,  but  not  more  than  about 
8  grains  for  each  yolk. 

The  quantity  of  yolk  of  egg  to  be  used  for  a  dozen  skins  de- 
pends on  the  size  of  the  latter,  and  whether  they  have  been 
washed  more  or  less.  It  can  only  be  said  that  from  3  to  12 
yolks  will  have  to  be  used  for  a  dozen  skins. 

Besides  oil  of  egg,  the  use  of  glycerin  has  been  found  to  give 
excellent  results,  the  leather  acquiring  great  pliancy,  since 
glycerin  possesses  the  property  of  not  drying  up. 

The  operation  of  nourishing  is  effected  in  a  vat  capable  of 
holding  about  ten  dozen  skins.  Fill  the  vat  about  half  full  of 
water  and  stir  in  the  yolk  of  egg  so  that  a  uniform  milky  fluid 
is  formed.  This  is  best  effected  by  beating  up  the  yolks  of  egg 
in  a  special  vessel  with  water,  adding  about  three  drachms  of 
glycerin  for  each  yolk  of  egg  used  and  mixing  the  whole  with 
the  water  in  the  vat.  The  washed  skins  being  well  squeezed 
are  best  suspended  to  cross-pieces  by  pairs  so  that  the  sides  not 
to  be  dyed  touch  each  other,  it  being  of  chief  importance  that 
the  side  to  be  dyed  be  provided  with  nourishment.  The  skins 
are  allowed  to  remain  in  the  vat  twelve  to  fourteen  hours  and, 
as  a  rule,  they  will  have  absorbed  all  the  nourishment.  Should, 
however,  any  of  the  latter  remain  after  lifting  the  skins  from  the 
vat,  it  is  used  in  the  preparation  of  a  fresh  supply. 


THE  DYEING  OF  LEATHER. 


597 


PRESERVATION  OF  YOLK  OF  EGG. 

The  price  of  yolk  of  egg  being  subject  to  great  fluctuations, 
it  being,  for  instance,  much  lower  in  the  spring  than  in  the  fall, 
a  mode  of  preserving  it  for  any  length  of  time  may  here  be 
given.  Prepare  for  this  purpose  a  concentrated  solution  of 
salicylic  acid  in  water  by  adding  2]^  drachms  of  salicylic  acid 
to  one  quart  of  water  in  an  enameled  pot,  then  heat  to  boiling 
with  constant  stirring,  and  allow  to  cool.  Salicylic  acid  re- 
quires about  300  parts  of  water  for  solution,  and  in  cooling  a 
portion  of  the  acid  is  again  separated  and  used  in  preparing 
fresh  solution. 

The  eggs,  the  yolks  of  which  are  to  be  preserved,  are  opened 
and  the  yolks  and  whites  carefully  separated.  The  whites 
may  in  a  fresh  state  be  directly  sold  to  cloth-printers,  or  they 
may  by  drying  upon  zinc  sheets  at  1360  F.  be  converted 
into  a  solid  mass,  which  may  be  kept  for  a  long  time.  The 
yolks  are  brought  into  a  vessel  and  intimately  mixed  with 
salicylic  acid  solution,  one  quart  of  the  latter  being  used  for 
three  quarts  of  the  former ;  thorough  stirring  and  mixing  being 
absolutely  necessary  for  proper  preservation.  The  resulting 
milky  fluid  is  stored  in  a  cool  place  in  large  glass  bottles,  which 
are  closed  with  parchment  papers  soaked  in  the  salicylic  acid 
solution. 

Yolks  thus  preserved  with  salicylic  acid  may  be  kept  for 
months  without  suffering  alteration.  In  dyeing,  the  acid  exerts 
no  influence  whatever,  except  with  the  use  of  iron  salts  it  would 
produce  a  red  color. 

Lanolin  or  wool-fat  is  particularly  well  adapted  for  leather 
nourishment,  it  imparting  to  the  leather  great  pliancy.  Lano- 
lin possesses  the  characteristic  property  of  mixing  with  an 
equal  quantity  by  weight  of  water  without  losing  its  fatty  nature. 
The  "degras"  used  so  largely  in  the  currying  of  grain  and 
split  leathers  is  really  lanolin — made  from  wool  fat. 


598 


THE  MANUFACTURE  OF  LEATHER. 


DYEING  TAWED  LEATHER  (GLACE  LEATHER). 

The  leather  may  be  dyed  either  by  the  so-called  dipping 
process  or  upon  the  board.  In  the  dipping  process  the  leather 
is  immersed  in  the  dyeing  liquor,  and,  according  to  the  old 
method,  treated  by  treading  with  the  naked  feet  until  it  has 
almost  entirely  absorbed  the  coloring  matter.  In  modern  * 
times  this,crude  method  has  been  replaced  by  suitable  apparatus. 

In  dyeing  upon  the  board,  only  one  side  of  the  leather  is 
actually  dyed,  the  lower  side,  when  the  work  is  properly  done, 
remaining  almost  entirely  white.  The  operation  is  executed  by 
applying  the  dyeing  liquor  to  the  leather  spread  on  a  level 
surface,  and  immediately  bringing  the  leather  into  the  dyeing 
chamber.  In  modern  times  the  dipping  process  has  been 
almost  entirely  replaced  by  dyeing  on  the  board,  since  the 
aniline  colors  which  are  now  almost  universally  used  are  sub- 
stantive colors,  and  the  leather  would  be  dyed  equally  strong 
on  both  sides  if  the  dipping  process  were  used.  The  latter 
method  is,  however,  still  employed  for  leather  to  be  dyed  pale 
tones  with  the  use  of  dyeing  liquors. 

DIPPING  PROCESS. 

The  older  method  of  executing  this  process  is  as  follows : 
The  lukewarm  dyeing  liquor  is  brought  into  a  vat  and  a 
number  of  skins,  with  the  side  to  be  dyed  up,  are  introduced. 
A  workman  then  enters  the  vat  and  by  moving  to  and  fro  with 
his  naked  feet,  endeavors  to  keep  the  skins  as  well  as  the  dye- 
ing liquor  in  constant  motion.  In  the  commencement  of  the 
operation  the  dyeing  liquor  becomes  rapidly  lighter,  the  color- 
ing matter  being  quickly  fixed  by  the  leather.  When  the  dye- 
ing liquor  is  exhausted  to  such  an  extent  as  to  be  plainly 
visible,  a  certain  quantity  of  fresh  dyeing  liquor  is  poured  into 
the  vat  and  treading  continued  until  the  pale  appearance  of 
the  dyeing  liquor  indicates  that  the  coloring  matter  has  been 
fixed.  Fresh  dyeing  liquor  is  then  again  introduced  and  the 
treading  and  adding  of  fresh  dyeing  liquor  continues  until  the 
desired  tone  of  color  is  obtained. 


THE  DYEING  OF  LEATHER. 


599 


It  will  be  readily  understood  that  before  each  addition  of 
fresh  dyeing  liquor  one  of  the  skins  has  to  be  taken  from  the 
vat  and  its  color  compared  with  the  sample,  as  otherwise  the 
tone  of  color  might  become  too  dark.  It  is  therefore  recom- 
mended to  make  an  accurate  note  of  the  quantity  of  dyeing 
liquor  required  to  dye  a  definite  number  of  skins  a  certain 
shade  of  color,  according  to  a  sample  book  kept  in  the  estab- 
lishment. The  data  thus  obtained  are  then  strictly  adhered  to 
with  slight  modifications  depending  on  the  size  of  the  skins  to 
be  dyed. 

It  seems  to  be  suitable  to  use  a  simple  dipping  apparatus 
with  the  assistance  of  which  one  workman  can  manipulate  with- 
out great  exertion  a  large  number  of  skins  at  one  time.  Such 
a  dipping  apparatus  is  shown  in  Fig.  147. 


Fig.  147. 


In  a  vat  of  the  form  shown  in  the  illustration  revolves  a 
wooden  wheel.  This  wheel  is  of  sufficient  width  that  a  skin  of 
a  certain  size  can  be  fastened  by  the  forefeet  to  two  nails  pro- 
jecting from  the  surface  of  the  wheel.  For  working  on  a 
larger  scale  the  wheel  is  given  the  form  of  a  drum,  and  suffi- 
cient width  to  suspend  three  or  four  skins  alongside  each  other. 
If,  for  instance,  the  wheel  is  6l/2  feet  in  diameter  its  circumfer- 
ence is  nearly  20  feet,  and  to  such  a  wheel,  which  is  only  wide 
enough  for  one  skin,  about  sixty  skins  can  be  suspended  ;  to  a 
wheel  with  two  widths  120  skins,  and  so  on.    The  nails  or 


600  THE  MANUFACTURE  OF  LEATHER. 

hooks  to  which  the  skins  are  suspended  consist  of  tinned  iron, 
and  are  bent  so  that  the  skins  secured  to  them  cannot  drop  ofif 
when  the  wheel  revolves.  These  nails  or  hooks  are  placed  at 
a  distance  of  3^  inches  from  each  other.  The  skins  are  sus- 
pended to  the  nails  with  the  sides  to  be  dyed  in  front. 

The  reservoir  (B)  is  placed  at  a  higher  level,  and  contains 
the  dyeing  liquor.  The  pipe  (R)  issuing  from  the  bottom  of 
the  reservoir  is  divided  into  two  branches  which  run  along  the 
side  of  the  vat  to  the  centre  and  then  branch  off  at  a  right  angle. 
The  portion  bent  downward  is  provided  with  narrow  perfora- 
tions. For  discharging  the  fluid,  the  lower  part  of  the  vat  is 
provided  with  a  pipe  furnished  with  a  stop-cock. 

The  manner  of  operating  this  apparatus  is  very  simple.  The 
vat  is  filled  with  sufficient  water  so  that  the  skins  are  moistened 
on  revolving  the  wheel.  In  order  to  moisten  every  skin  the 
wheel  is  allowed  to  revolve  once  and  the  stop-cock  on  the 
reservoir  (B)  is  then  opened  to  admit  the  dyeing  liquor.  The 
wheel  is  now  kept  constantly  revolving.  One  skin  after  the 
other  dips  into  the  dye  bath  and  after  absorbing  a  certain 
quantity  of  the  coloring  matter  is  lifted  from  the  bath,  thus 
assuring  uniform  treatment  of  each  skin.  When  dyeing  is 
almost  completed,  the  pipe  admitting  the  dyeing  liquor  is 
closed  either  partly  or  entirely,  and  after  revolving  the  wheel  a 
few  times  more,  the  bath  is  discharged  from  the  vat.  The  dyed 
skins  are  taken  one  after  the  other  from  the  wheel  and  brought 
into  the  drying  chamber. 

The  use  of  this  apparatus  offers  the  advantage  that  not  only 
a  considerable  number  of  skins  can  be  treated  at  one  time,  but 
also  that  the  progress  of  the  dyeing  operation  can  at  every 
moment  be  inspected,  since  a  certain  number  of  skins  are  con- 
stantly lifted  from  the  bath. 

When  the  skins  have  been  taken  from  the  dyeing  liquor  they 
are  generally  brought  into  a  bath  of  yolk  of  egg,  then  pressed 
quite  vigorously  by  passing  through  between  two  very  smooth 
rolls — the  so-called  glazing  rolls — and  brought  into  the  drying 
chamber. 


THE  DYEING  OF  LEATHER. 


60  I 


DYEING.  UPON  THE  BOARD. 

For  dyeing  upon  the  board  the  following  utensils  are  re- 
quired:  A  dyeing  table,  reservoirs  for  the  mordants,  dye-stuffs 
and  toning  fluids  and  brushes.  These  utensils  should  be  so 
arranged  that  the  workman  can  work  without  interruption,  and 
the  following  arrangement  may  be  recommended  as  very 
suitable : 

The  dyeing  table  or  board  should  be  perfectly  level,  and  the 
plate  consist  of  a  material  which  does  not  absorb  moisture,  nor 
exert  a  chemical  action  upon  the  leather.  The  most  suitable 
material  for  this  purpose  is  zinc,  since  a  sheet  of  this  material 
can  be  readily  secured  to  a  thick  wooden  plate  by  bending  it 
over  the  edges  of  the  narrow  ends  of  the  latter.  The  use  of 
nails  should  be  avoided.  The  plate  of  the  table  should  be 
fixed  so  as  to  be  about  three-fourths  inch  lower  to  the  right 
than  to  the  left,  and  on  the  right-hand  narrow  side,  underneath 
the  sheet,  a  small  gutter  is  provided  beneath  which  a  tub  is 
placed. 

The  fluids  required  in  dyeing  should  be  placed  in  the  order 
used  by  the  workman  ;  the  vessel  containing  the  mordant  to 
the  left,  the  vessel  with  the  dyeing  liquor  in  the  center,  and 
that  with  the  toning  liquor  to  the  right.  Above  the  table 
hangs  a  rubber  hose  of  sufficient  size  to  throw  out  a  jet  of 
water  the  thickness  of  the  thumb,  when  the  cock  with  which 
it  is  fitted  is  opened.  Each  vessel  is  provided  with  a  brush 
of  soft,  quite  long  bristles  and, furnished  with  a  handle.  Each 
brush  should  be  used  only  for  a  certain  fluid,  and  when  the 
work  is  finished  be  immediately  cleansed  by  thorough  washing. 
In  place  of  brushes  many  dyers  use  large  bath-sponges  tied  to 
handles.  For  dyeing  it  is  of  course  indifferent  whether  the 
work  is  done  with  brushes  or  sponges,  the  principal  thing  being 
the  uniform  application  of  the  coloring  matter. 

The  operation  of  dyeing  is  commenced  by  spreading  the 
skin  to  be  dyed  perfectly  smooth  on  the  table  and  removing 
every  wrinkle  by  gentle  rubbing  with  a  rounded  off  wooden 


602 


THE  MANUFACTURE  OF  LEATHER. 


tool.  The  mordant  is  then  applied,  next  the  coloring  matter, 
and  finally  the  toning  fluid.  With  the  use  of  aniline  colors  it 
is  only  necessary  to  apply  the  coloring  matter. 

To  avoid  the  formation  of  stains  the  workman  should  take 
just  sufficient  fluid  in  the  brush  completely  to  brush  over  one 
skin,  and  he  should  endeavor  to  apply  the  fluid  uniformly  to 
all  portions  of  the  skin.  Whether  he  does  this  by  carrying  the 
brush  in  a  spiral  line  or  in  a  zigzag  over  the  skin  is  entirely 
optional,  the  principal  thing  being  that  he  works  uniformly. 

With  the  use  of  dye-stuffs  obtained  from  decoctions  of  vege- 
table substances  a  mordant  consisting  of  a  dilute  solution  of  an 
alkaline  carbonate  is  generally  first  applied.  The  action  of 
this  mordant  is  as  follows:  By  the  alkali,  alumina  in  the  form 
of  a  precipitate  is  separated  from  the  alum  contained  in  the 
leather,  and  this  freshly  precipitated  alumina  combines  very 
rapidly  with  the  coloring  matter,  so  that  the  latter  is  more 
completely  and  more  quickly  fixed.  If  sufficient  alkali  is  pres- 
ent it  acts  also  upon  the  salts  used  in  toning  by  separating  the 
respective  metallic  oxide,  which  combines  immediately  with  the 
coloring  matter. 

Very  dilute  solutions  of  potash  or  soda  are  now  used,  5  parts 
by  weight  of  potash  or  soda  in  100  parts  of  water  being  suffi- 
cient. 

The  skin  having  been  uniformly  moistened  either  with  the 
alkaline  mordant  alone,  or  first  with  a  tin  salt  mordant  and  then 
with  the  alkaline  mordant,  the  dyeing  liquor  is  immediately 
applied,  the  application  being  repeated  until  the  desired  shade 
of  color  is  obtained,  when  the  work  is  finished  by  applying  the 
toning  fluid. 

When  working  with  aniline  colors  it  is  only  necessary  uni- 
formly to  apply  the  solution  of  the  coloring  matter  to  the  skin 
and  to  repeat  the  operation  until  the  desired  shade  is  pro- 
duced. 

The  dyeing  operation  being  finished,  the  workman  by  open- 
ing the  cock  on  the  rubber  hose  allows  water  to  flow  over  the 
skin,  turns  it  around,  and  after  rinsing  the  back  removes  the 


THE  DYEING  OF  LEATHER. 


603 


excess  of  water  by  vigorously  rubbing  the  back  of  the  skin  with 
a  tool  provided  for  the  purpose.  He  then  spreads  the  skin, 
dyed  side  up,  on  a  table  standing  alongside  the  dyeing  table. 
The  skin  dyed  next  is  laid,  dyed  side  down,  upon  the  first,  the 
third  dyed  side  up,  the  fourth  dyed  side  down,  and  so  on. 

The  workman  having  dyed  a  skin  rinses  the  plate  with  water 
to  remove  any  remaining  coloring  matter  which  might  discolor 
the  back  of  the  next  skin,  and  then  proceeds  with  the  opera- 
tion. 

DYES  AND  TONING  FLUIDS. 

The  color  mixtures  which  are  particularly  employed  for 
tawed  leather  have  been  previously  referred  to,  and  but  little 
remains  to  be  added.  It  is  considered  unnecessary  to  give 
definite  receipts,  since  they  would  produce  only  one  tone  of  the 
respective  color,  while  the  modifications  of  one  and  the  same 
color  are  very  numerous.  It  is,  therefore,  decidedly  preferable 
to  have  given  to  our  readers  the  methods  by  which  a  perma- 
nent sample  card  of  colors  and  their  modifications  can  be  ob- 
tained, namely,  by  systematic  dilution  of  dyeing  liquors  and 
subsequent  mixing.  Such  colors  and  modifications  once 
determined  and  entered  in  the  sample  book  can  always  be 
reproduced. 

Regarding  the  aniline  colors,  it  may  be  remarked  that  by 
reason  of  their  great  dyeing  power  they  should  be  used  only  in 
the  form  of  very  dilute  solutions.  Thirty  to  forty-five  grains  of 
aniline  color  dissolved  in  a  fluid  are  sufficient  for  the  produc- 
tion of  beautiful  colors,  and  the  dyer  by  applying  twice  or  three 
times  such  solutions  of  moderate  concentration  can  readily 
obtain  any  shade  desired. 

Indigo  carmine  being  next  to  the  aniline  colors  as  regards 
dyeing  power  must  also  be  used  in  dilute  solution.  To  avoid 
defects  the  solutions  of  aniline  colors  and  of  indigo  carmine 
should  be  filtered  before  use.  If,  for  instance,  the  dyeing 
liquor  holds  in  suspension  a  scarcely  perceptible  solid  particle 
of  aniline  color,  the  consequence  would  be  that  in  applying  the 


604 


THE  MANUFACTURE  OF  LEATHER. 


liquor  with  the  brush,  this  particle  would  produce  a  very  dark- 
colored  streak,  and  the  coloring  of  the  leather  would  thereby 
become  defective. 

As  dyes,  in  the  actual  sense  of  the  word,  it  is  best  for  colors 
of  a  pure  tone  to  use  aniline  colors,  namely,  for  red  and  its 
modifications,  fuchsin  ;  for  yellow,  picric  acid;  for  green,  iodine 
green ;  for  blue,  indigo  carmine  or  aniline  blue ;  for  violet, 
methyl-violet.  These  colors  may  be  modified  by  mixing  with 
other  colors,  yellow,  for  instance,  being  changed  to  orange  by 
adding  red  ;  red  into  purple  by  adding  blue,  and  so  on. 

For  dying  glace  leather  intended  for  fancy  goods,  the  use  of 
aniline  colors  may  be  recommended  as  most  suitable;  but  for 
dyeing  glove  leather  blended  colors,  such  as  brown,  gray  and 
olive  green,  which  are  at  present  very  much  in  demand,  liquors 
of  dye  stuffs  are  to  be  preferred. 

While  formerly  the  dyer  had  to  use  a  larger  number  of  dye- 
stuffs  in  order  to  obtain  a  certain  shade,  at  present  decoctions 
of  fustet,  Brazil  wood,  logwood  and  alder  bark  suffice  for  most 
purposes.  The  modifications  of  the  colors  are  effected  besides 
with  the  use  of  toning  fluids  by  small  additions  of  aniline 
colors,  such  as  picric  acid,  fuchsin  or  water-soluble  blue,  to  the 
mixed  decoctions. 

DIRECTIONS  FOR  THE  PRODUCTION  OF  BLENDED  .COLORS  UPON  GLACE 


A  number  of  receipts  are  here  given  according  to  which  the 
most  important  blended  colors,  especially  those  used  for  glazed 
glove  leather,  may  be  prepared. 

The  receipts  marked  II.  give  colors  which  may  be  designated 
the  medium  shades  of  the  respective  colors,  while  No.  I.  yield 
very  light  and  No.  III.  very  dark  shades.  The  figures  refer  to 
units  of  fluid  of  the  concentrated  dye  liquors: 

Light  ochre  yellow  and  maize  yellow,  decoction  of: 


LEATHER. 


I. 


II. 


III. 


Fustet  

Brazil  wood 
Logwood  . . 


25 
30 


5° 
1 2% 


THE  DYEING  OF  LEATHER. 


605 


Dark  gold  ochre  to  umber,  decoction  of: 


I. 

II. 

III. 

 ...:::'6 

5 

45 

 £:.-..\v%Vg' 

1 1 

20 

1 1 

14 

Wood  brown  to  mahogany  color,  decoction  of: 


I. 

II. 

III. 

13 

24 

16 

   6 

53 

Reddish  brown  to  Venetian  red,  decoction  of : 


I. 

II. 

III. 

  1% 

25 

5° 

•••"••""•■"'5 

30 

3 

1% 

Brownish  red  (Pompeian  red),  decoction  of: 


I. 

II. 

III. 

  52 

6 

5° 

  5 

26 

3 

1 1 

1% 

Pure  Havana  brown,  decoction  of: 

I.  II.  III. 

Fustet   50  50  50 

Brazilwood   27}/*  10  7% 

Logwood   2%         7  1 

Sienna  brown,  decoction  of : 

I.  II.  III. 

Fustet   50  $z%  9 

Brazilwood   9  8  32)^ 

Logwood   1  6 

Dark  bister  brown,  decoction  of: 

I.  II.  III. 

Fustet     50  30  50 

Brazil  wood   1  7%  15 

Logwood   2  10  2% 


6o6 


THE  MANUFACTURE  OF  LEATHER. 


Olive,  decoction  of: 


I. 

II. 

III. 

  5° 

5° 

5 

  5 

IO 

5° 

27^ 

IO 

Red  brown  to  dark  brown,  decoction  of: 


I. 

II. 

III. 

  15 

25 

37)4 

  37^ 

25 

12% 

  4 

i7M 

4 

Green  brown  to  dark  brown,  decoction  of: 


I. 

II. 

III 

 :  37K 

22% 

3 

  4 

30 

  6 

I2>2 

'5 

Lac  brown  and  dark  brown,  decoction  of : 


I. 

II. 

III. 

  S2H 

37>2 

30 

  3 

27K 

  6 

1% 

5 

Sepia  brown,  decoction  of: 


I. 

II. 

III. 

 42M 

40 

  2714 

3 

™% 

  18 

16 

40 

Iron  violet,  decoction  of: 


I. 

II. 

III. 

  16 

27 

5° 

•   36 

14 

1 

6 

6 

Gray  blue  (dark  pigeon  gray),  decoction  of: 


I. 

II. 

III. 

  25 

3° 

5° 

  5 

9 

15 

  25 

32^ 

4 

THE  DYEING  OF  LEATHER. 


607 


Slate  gray,  decoction  of: 


I. 

II. 

III. 

35 

5° 

32^ 

5° 

Iron  or  steel  gray,  decoction  of: 


I. 

II. 

III. 

1 1 

30 

6 

1 

14 

27)-. 

 27% 

37^ 

5° 

Light  ash  gray,  decoction  of: 


I. 

II. 

III. 

5° 

30 

6 

30 

  30 

1 1 

10 

1% 

2 

It  only  remains  to  give  here  the  toning  fluids  to  be  used  for 
the  different  broken  colors,  and  to  mention  that  the  numbers 
of  the  separate  fluids  are  so  placed  that  in  this  case  the  higher 
number  also  produces  a  deeper  tone. 

Mixtures  of  various  quantities  of  decoctions  of  fustet,  Brazil 
wood  and  logwood  are  used  for: 

Light  ochre  yellow,  maize  yellow  to  dark  gold  ochre  yellow : 
Toning  with  alum  for  the  light  shades,  and  with  sulphate  of 
zinc  for  the  darker  shades. 

Light  wood  brown  to  sad  mahogany  color :  Toning  with  sul- 
phate of  zinc. 

Havana  brown  through  red  to  an  indefinite  olive  color:  For 
the  lighter  shades  sulphate  of  copper  1  and  2,  for  the  darker 
shades  3  and  4. 

Lac  brown  and  dark  brown,  with  sulphate  of  copper  1  and  2. 

For  slate  gray  in  all  its  modifications :  Copperas  1  to  4. 

For  iron  violet  in  all  its  modifications :  Sulphate  of  copper  1 
to  4. 

For  reddish  violet:  Sulphate  of  zinc. 


6o8 


THE  MANUFACTURE  OF  LEATHER. 


Mixtures  of  various  quantities  of  fustet,  Brazil  wood  and  log- 
wood besides  elder  bark  are  used  for : 
Stone  gray  with  copperas  I  and  2. 
Olive  green  with  copperas  I,  2  and  3. 
Gray  green  with  copperas  I  and  2. 
Steel  gray  with  copperas  2. 

Remarks :  A  quite  satisfactory  black  may  also  be  produced 
by  a  mixture  of  decoctions  of  fustet,  Brazil  wood  and  logwood, 
in  which  the  latter  should  especially  preponderate,  and  with 
the  use  of  a  toning  fluid  containing  potassium  chromate  in 
solution.  However,  the  process  does  not  suffice  for  the  pro- 
duction of  a  pure  lustrous  black,  and  dyeing  leather  black 
forms  a  special  branch  of  the  glace  leather  dyeing  industry. 

In  conclusion  it  may  be  added  that  the  above  mentioned  in- 
structions regarding  shades  of  color  and  toning  fluids  refer  to 
dyeing  upon  the  board.  The  lighter  modifications  of  these 
colors,  especially  ochre  yellow  and  pale  green,  may  also  be 
produced  by  dipping,  but  in  this  case  the  dye  liquor  should  be 
somewhat  darker,  as  the  color  is  not  toned. 

MIXED  COLORS. 

This  term  may  be  applied  to  colors  produced  from  a  mineral 
color — Berlin  and  chrome  yellow — and  an  organic  dyestuff. 
While  these  colors  were  formerly  quite  frequently  used  for  the 
production  of  neat  effects,  they  have  at  present  been  almost 
entirely  abandoned,  the  aniline  colors  being  by  far  more  con- 
venient for  obtaining  the  same  shades. 

Dyeing  with  mineral  colors  is  effected  by  giving  a  mordant 
consisting  of  a  salt,  applying  upon  this  the  solution  of  another 
salt,  whereby  either  pure  blue  or  pure  yellow  is  obtained. 
Now  by  laying  upon  the  blue  pure  yellow,  green  is  obtained  ; 
by  using  pure  red,  violet  is  formed;  or  by  laying  pure  red 
upon  chrome  yellow,  orange — in  one  word,  every  shade  of  color 
may  in  this  manner  be  obtained,  the  production  of  agreeable 
modifications  being  in  this  case  largely  dependent  on  the  skill 
of  the  workman  in  harmonizing  the  colors. 


THE  DYEING  OF  LEATHER. 


609 


Thus,  for  instance,  by  applying  picric  acid  solution  to  leather 
dyed  with  Berlin  blue,  all  shades  from  pale  grass  green  to  dark 
malachite  green  may  be  produced ;  light  olive  green  upon 
leather  dyed  with  Berlin  blue  is  obtained  with  quercitron  and 
archil. 

In  the  reverse  manner,  by  applying  water-soluble  blue  to 
leather  dyed  with  chrome  yellow,  various  shades  of  green  may  be 
produced,  while  by  the  use  of  fuchsin  orange  is  obtained,  by  the 
use  of  elder  bark,  sallow  shades  with  a  grayish  tinge,  and  so  on. 

For  the  production  of  all  these  colors  the  leather  has  to  be 
handled  three  times,  namely,  mordanting,  dyeing  and  apply- 
ing the  organic  coloring  matter,  while  in  working  with  aniline 
colors  the  desired  shade  is  obtained  by  one  manipulation. 

DYEING  LEATHER  BLACK. 

Dyeing  leather  black  is  by  many  considered  a  special  art, 
but  actually  it  is  not  more  difficult  than  any  other  color,  the 
only  thing  necessary  being  the  proper  choice  of  the  dyestuff. 

If  a  fluid  containing  tannin  in  solution,  for  instance,  a  decoc- 
tion of  tan-bark,  gall-nuts,  etc.,  be  compounded  with  an  iron 
salt,  it  is  immediately  colored  deep  black,  and  this  process  was 
formerly  exclusively  employed  in  the  manufacture  of  ink,  the 
very  delicate  precipitate  formed  in  the  fluid  being  held  in  sus- 
pension by  the  addition  of  gum  solution. 

By  diluting  the  solutions  of  the  tannin  and  of  the  iron  salt, 
and  pouring  them  together,  it  will  be  observed  that  the  fluid  is 
not  black,  but  rather  green  or  blue,  and  the  coloration  depends 
on  the  nature  of  the  tannin  used  as  well  as  on  that  of  the  iron 
salt  (ferrous  or  ferric  oxide).  The  color  appears  black  to  the 
eye  only  when  the  fluids  are  in  a  more  concentrated  state,  but 
always  with  an  admixture  of  green  or  blue,  so  that  actually  we 
have  only  a  very  dark  green  or  blue,  but  not  a  black.  By 
applying  a  fluid  containing  tannin  to  leather  previously  mor- 
danted with  iron  salt  (copperas  or  acetate  of  iron),  a  precipi- 
tate is  formed,  and  the  leather  is  colored  blue-black  or  green- 
black. 

39 


6io 


THE  MANUFACTURE  OF  LEATHER. 


By  adding  to  a  decoction  of  logwood  a  very  small  quantity 
of  potassium  chromate  solution,  the  fluid  is  immediately  col- 
ored deep  black-blue  without,  however,  a  precipitate  being 
formed  The  chemical  process  of  this  phenomenon  is  not  yet 
thoroughly  understood,  but  it  is  supposed  that  a  soluble  chrome 
combination  of  the  coloring  matter  is  formed. 

Now  this  behavior  of  bodies  containing  tannin  towards  iron 
salts  or  that  of  logwood  decoction  towards  potassium  chromate 
may  be  utilized  for  dyeing  leather  black,  but  very  frequently 
mixed  fluids  are  used. 

DYEING  WITH  TANNIN  AND  IRON  SALTS. 

This  mode  of  dyeing  is  seldom  used  for  finer  qualities  of 
leather,  but  frequently  for  shoe  leather.  For  dyeing  tanned 
leather  it  is  only  necessary  to  apply  the  solution  to  the  leather, 
the  tannin  contained  in  the  latter  being  sufficient  to  produce 
coloration.  However,  as  a  rule,  the  leather  is  first  treated  with 
a  decoction  of  tanning  material,  generally  of  gall-nuts  or  sumac, 
and  then  dyed  with  the  iron  salt.  It  is  recommended  to  ascer- 
tain, previously  to  dyeing,  the  proper  constitution  of  the  solu- 
tion by  a  small  experiment,  because  with  the  use  of  too  small 
a  quantity  of  tannin  the  resulting  color  will  not  be  dark  enough, 
but  show  a  sallow  tone.  It  is  also  of  importance  not  to  use 
more  of  the  iron  salt  than  absolutely  necessary,  since  exper- 
ience has  shown  that  an  excess  renders  the  leather  brittle. 

DYEING  WITH  LOGWOOD  AND  POTASSIUM  CHROMATE. 

The  solution  of  the  logwood  coloring  matter  may  be  pre- 
pared either  by  boiling  rasped  logwood  with  water,  or  by  dis- 
solving solid  logwood  extract  in  water.  In  working  according 
to  the  first  process  it  is  best  to  prepare  a  completely  saturated 
solution  of  the  dye-stuff  by  boiling  a  large  quantity  of  the 
wood  for  several  hours  and  straining  the  solution.  However, 
working  with  solid  logwood  extract  is  much  more  convenient, 
since  by  a  few  experiments  it  can  be  readily  ascertained  how 
much  water  has  to  be  taken  for  a  certain  quantity  of  extract  in 
order  to  obtain  a  dyeing  liquor  of  the  proper  concentration. 


THE  DYEING  OF  LEATHER. 


The  leather  is  treated  with  the  solution  of  the  dye-stuff  and 
then  brushed  over  with  the  solution  of  potassium  chromate. 
For  this  purpose  the  toning  fluid  No.  i  may  be  used,  but  it 
must  be  suitably  diluted  with  water. 

By  using  the  solution  of  logwood  extract  in  a  too  concen- 
trated state  it  will  be  observed  that  the  color  acquires  a  pecu- 
liar metallic  luster  which  should  be  avoided  in  dyeing  black, 
and  this  can  be  done  by  simply  diluting  the  solution  with 
water. 

With  proper  concentration  of  both  fluids  a  beautiful  black 
with  a  bluish  tinge  is  immediately  obtained.  This  bluish  tinge 
may  be  heightened  by  adding  to  the  logwood  decoction  a 
small  quantity  of  indigo  carmine,  or  by  slightly  dyeing  the 
leather  with  aniline  blue  before  applying  the  logwood  solution. 

DYEING  WITH  TANNIN  AND  LOGWOOD. 

The  majority  of  leather  dyers  prefer  mixtures  of  the  colors, 
which  can  be  produced  by  tannin  and  logwood,  and  there  is 
good  reason  for  this  preference,  because  the  tannin  color  is 
generally  somewhat  greenish  and  the  logwood  color  bluish, 
while  both  together,  with  a  little  fustic  decoction,  give  black. 

A  receipt,  according  to  which,  for  instance,  a  very  beautiful 
black  upon  leather  may  be  obtained,  is  as  follows :  Boil  tan 
100  parts,  logwood  25,  fustic  12,  water  250.  Apply  the  re- 
sulting liquor  to  the  leather,  and  then  solution  of  copperas,  to 
which  a  small  quantity  of  nitric  acid  has  been  added,  or  solu- 
tion of  acetate  of  iron.  A  still  better  result  is  obtained  by 
adding  to  the  iron  solution  a  small  quantity  of  potassium 
chromate. 

The  methods  of  dyeing  black  described  above  may  be  used 
for  tanned,  chamois  and  tawed  leather.  In  dyeing  the  latter, 
especially  thin  skins,  care  must  be  taken  to  prevent  the  dye 
from  penetrating  the  leather,  which  is  best  effected  by  applying 
to  the  side  to  be  colored,  prior  to  the  actual  dyeing,  solution  of 
soda  or  potash,  and  by  using  the  dyeing  liquor  no  more  diluted 
than  is  absolutely  necessary. 


6l2 


THE  MANUFACTURE  OF  LEATHER. 


DEEP  BLACK  N1GROSIN  COLOR. 

Dissolve  40  parts  borax  in  800  parts  water  by  heating,  bring 
gradually  into  the  solution  150  parts  pulverized  brown  shellac 
and  boil  until  all  the  shellac  is  dissolved,  from  time  to  time  re- 
placing the  water  lost  by  evaporation.  Now  triturate  40  parts 
nigrosin  (aniline  black)  with  a  portion  of  the  solution  to  a  thick 
milky  fluid  which  is  finally  intimately  mixed  with  the  remainder 
of  the  borax-shellac  solution.  This  preparation,  when  applied 
with  a  brush,  gives  a  lustrous,  deep  black  color  immediately 
after  drying. 

BLUE  BLACK  NIGROSIN  COLOR. 

I.  Dissolve  in  400  parts  water,  30  parts  borax  and  3  parts  ' 
caustic  soda,  introduce  130  parts  brown  shellac  and  boil  until 
the  latter  is  dissolved. 

II.  Dissolve  in  300  parts  water,  50  parts  logwood  extract,  20 
parts  aniline  deep  black,  and  add  IO  parts  glycerin.  Accord- 
ing to  whether  the  color  is  to  show  a  more  or  less  blue  tinge 
add  5  to  10  parts  methyl-blue. 

III.  Compound  the  mixture  of  solutions  I.  and  II.  with  50 
parts  of  a  20  per  cent,  acetate  of  iron  solution  and  90  parts 
water. 

Actual  high  lustre  is  imparted  to  leather  dyed  black  only  by 
the  so-called  polishing  or  glossing,  and  this  operation  has  to  be 
distinguished  from  glazing,  to  which  tawed  leather  of  other 
colors  is  subjected. 

GLAZING  AND  GLOSSING  OF  LEATHER. 

Glazing. — This  operation  is  executed  in  various  ways,  but 
best  with  the  use  of  a  decoction  of  flaxseed  mixed  with  solution 
of  white  soap.  The  flaxseed  contains  a  mucous  substance 
which  dissolves  in  water  by  long  boiling  and  in  drying  forms  a 
lustrous  mass  which  does  not  possess  the  hard  glossy  luster  of 
gum. 

The  glazing  fluid  is  prepared  as  follows:  Wash  the  flaxseed 
in  cold  water  to  remove  adhering  dust,  and  then  boil  it  with 


THE  DYEING  OF  LEATHER. 


613 


four  or  five  times  the  quantity  of  water  for  one  hour.  Filter  the 
cold  fluid  through  a  closely  woven  cloth  into  an  enameled  ves- 
sel for  the  purpose  of  boiling  with  the  soap.  Use  pure  white 
grain  soap  free  from  any  disagreeable  odor.  Convert  the  soap 
into  thin  shavings,  introduce  the  shavings  in  small  portions  at 
a  time  into  the  boiling  fluid  and  promote  solution  by  vigorous 
stirring.  From  time  to  time  take  a  sample  from  the  vessel  and 
cool  it  rapidly.  If  it  forms  a  slippery,  slightly  opalescent  fluid, 
the  solution  contains  enough  soap  and  is  then  again  strained 
through  a  cloth.  Add  to  the  cold  fluid  a  few  yolks  of  egg,  and 
beat  up  the  whole  until  a  uniform  mass  is  formed. 

By  adding  to  the  boiling  fluid  some  olive  oil,  at  the  utmost 
5  per  cent,  of  the  quantity  of  soap  used,  a  glazing  fluid  is  ob- 
tained which  imparts  to  the  leather  greater  flexibility  than  is 
obtained  with  the  above-mentioned  fluid. 

The  glazing  fluid  is  applied  to  the  leather  in  a  manner  similar 
to  the  coloring  matter,  care  being  however  taken  to  put  it  on 
in  a  very  thin  layer,  since  the  thinner  the  layer  the  more  beau- 
tiful the  luster  will  be.  It  is  best  to  use  a  large  soft  bath-sponge 
which  after  being  dipped  in  the  fluid  and  squeezed  out,  is 
passed  with  slight  pressure  over  the  leather.  Immediately 
after  drying  the  leather  shows  a  beautiful  luster,  which  may  be 
still  further  heightened  by  passing  the  leather  through  between 
two  rapidly  revolving  rolls  covered  with  flannel. 

Tawed  leather,  not  dyed,  is  glazed  in  the  same  manner  as 
described  above,  with  the  exception  that  the  glazing  fluid  is 
applied  twice,  since  undyed  leather  absorbs  more  of  the  fluid 
than  dyed  leather,  and  hence  one  application  would  not  pro- 
duce a  high  luster. 

In  place  of  the  above  described  glazing  a  solution  of  solid 
white  of  egg,  so  called  patent  albumin,  in  water  with  an  addi- 
tion of  about  5  per  cent,  of  the  weight  of  albumin  used,  of 
glycerin,  may  be  employed.  With  proper  concentration  of  this 
albumin  solution,  a  glazing  fluid  is  obtained  which  with  one 
application  and  subsequent  passing  through  between  the 
flannel-covered  rolls,  imparts  to  the  leather  a  high  luster. 


614 


THE  MANUFACTURE  OF  LEATHER. 


Glossing. — Glossing  of  ordinary  leather  is  very  frequently 
effected  by  brushing  the  leather  over  with  a  rind  of  bacon  and 
rubbing  with  a  cotton  ball  covered  with  linen  until  the  desired 
luster  is  produced.  For  finer  qualities  of  leather  a  glossing 
mass  consisting  of  a  fat-emulsion,  which  also  contains  soap, 
may  be  advantageously  used.  Such  glossing  mass  of  excellent 
quality  may  be  produced  by  boiling  a  good  grade  of  white 
grain  soap  with  five  times  the  quantity  of  water  until  a  perfectly 
clear  soap  paste  is  obtained,  and  adding  to  this  soap  solution, 
oil  and  a  certain  quantity  of  stearic  acid.  The  effect  of  the 
alkali  in  the  soap  and  the  soda  is  that  after  continued  stirring 
the  oil  is  divided  into  very  fine  drops,  and  an  emulsion  is 
formed.  By  rubbing  the  leather  with  this  mass  it  absorbs  the 
oil,  which  renders  it  pliable,  while  an  agreeable  gloss  is  im- 
parted by  the  soap.  A  glossing  mass  suitable  for  the  most 
delicate  colors  may  be  prepared  according  to  the  following 
formula : 


White  grain  soap   2  lbs. 

Water   5  qts. 

Soda   14  ozs. 

Dissolved  in  water   21  ozs. 

Olive  oil   17  ozs. 

Stearic  acid   5  ozs. 


Introduce  the  soap  solution  into  the  soda  solution  and  then 
add  the  oil  and  the  stearic  acid.  Heat  to  from  140°  to  1 5 8°  F., 
and  stir  until  the  whole  forms  a  uniform,  milky  mass. 

After  applying  the  glossing  mass  draw  the  leather,  colored 
side  down,  over  a  dull  blade,  and  finally  rub  it  with  the  above 
mentioned  cotton  ball.  In  place  of  the  latter  an  apparatus 
may  be  used  which  consists  of  two  wooden  rolls,  the  lower  one 
of  which  is  covered  with  rubber  and  the  upper  one  with  cloth, 
which,  however,  should  not  be  too  rough.  The  leather,  colored 
side  up,  is  placed  upon  the  lower  roll  and,  while  the  upper  roll 
revolves  rapidly,  allowed  slowly  to  pass  through.  It  must,  of 
course,  be  held  on  one  side,  otherwise  it  would  be  carried 


THE  DYEING  OF  LEATHER. 


6l5 


along  by  the  rolls.  By  this  treatment  the  leather  acquires  a 
beautiful  lustre,  and  this  operation  in  most  dyeing  establish- 
ments finishes  the  manipulation. 

While  formerly  soap-like  bodies  or  fat-emulsions  (degras) 
were  exclusively  used  for  rendering  the  leather  pliable  and  for 
glossing,  in  modern  times  these  substances  are  frequently  re- 
placed by  bodies  obtained  in  the  manufacture  of  petroleum, 
such  as  vaseline,  or  by  products  of  the  tar  industry,  such  as 
paraffin  and  paraffin  oil.  Compared  with  fat-like  substances 
they  have  the  advantage  of  not  containing  free  acids  and  not 
becoming  rancid. 

In  a  pure  state  vaseline  is  white  or  yellowish,  of  salve-like 
consistency,  liquefies  by  slight  heating  and  readily  penetrates 
the  leather,  imparting  to  it  permanently  a  high  degree  of 
pliancy.  Paraffin  is  at  the  ordinary  temperature  a  solid  crys- 
talline body  of  alabaster-like  appearance,  and  melts  on  heating. 
There  are  varieties  of  paraffin  with  a  melting  point  above  1 5 8° 
F.,  but  while  excellent  for  the  manufacture  of  candles,  they  are 
not  suitable  for  our  purpose.  However,  from  the  hardest 
varieties  down  there  are  a  large  number  of  paraffins  whose 
melting  points  are  much  lower,  and  which  are  soft  like  warmed 
wax.  Such  paraffins,  as  well  as  those  liquid  at  the  ordinary 
temperature — so-called  paraffin  oils — are  especially  suitable  for 
making  leather  pliable,  and  for  glossing  purposes.  They  may 
be  used  either  by  themselves  or  melted  together  with  carnauba 
wax,  turpentine,  etc. 

GLAZING  ROLLS. 

Passing  the  leather  through  between  glazing  rolls  is  a  very 
suitable  operation,  it  acquiring  thereby  not  only  a  high  luster, 
but  also  uniform  thickness.  The  apparatus  consists  of  two 
smooth  rolls  forced  together  by  a  loaded  lever  which  presses 
uniformly  upon  the  bearings  of  the  upper  roll.  The  leather  to 
be  glazed  is  placed  between  two  polished  sheets  of  zinc,  so  that 
no  wrinkles  are  visible,  and  then  passed  slowly  through  be- 
tween the  rolls. 


6i6 


THE  MANUFACTURE  OF  LEATHER. 


DYEING  RABBIT  SKINS  BLACK. 

First  the  hair  is  deadened  with  a  so-called  "  green  bath," 
which  is  composed  of  9  ozs.  green  vitriol,  1  oz.  acetate  of 
copper  crystals,  2^  ozs.  copper  ashes  and  1  quart  urine.  The 
skins  are  spread  upon  the  table,  as  usual,  and  the  hair  for  4 
hours  moistened  with  the  mixture  by  means  of  a  brush.  The 
green  looking  skin  is  then  dried  and  cleaned.  For  a  very  dark 
color  the  green  bath  is  once  or  twice  repeated.  Then  a  dye  is 
prepared  by  mixing  31^  lbs.  roasted  and  powdered  nutgalls  with 
the  solution  of  I  ^  ozs.  green  vitriol  in  y±  pint  boiling  water,  to 
which,  after  cooling,  3  quarts  water  is  added  under  stirring. 
The  skins  are  for  4  hours  moistened  with  the  dye,  dried,  again 
treated  with  a  mixture  of  I  pint  green  bath  and  ^  quart  urine, 
dried,  again  brushed  with  equal  parts  of  the  dye  and  warm 
water,  kept  moist  for  4  hours,  dried,  and  finally  cleaned  with 
bran,  brushing  and  currying. 

Or,  prepare  a  bath  containing  37^2  grains  potassium  bichro- 
mate and  i$/4  grains  cream  of  tartar  per  quart,  and  lay  down  in 
it  the  well-cleaned  skins  for  8  hours  at  86°  to  1040  F.  Then  take 
up,  rinse  well,  enter  a  bath  containing  per  quart  46^  grains 
Ursol  (Actien  Gesellschaft  fuer  Anilinfabrikation,  Berlin)  at 
86°  to  1040  F.,  turn  lively  at  first,  then  lay  down  for  three 
hours,  when  take  up  the  skins,  add  I OO  ccm.  hydrogen  peroxide 
per  quart,  re-enter,  lift  after  10  hours,  air  for  1  hour,  rinse  well 
and  dry.  If  not  deep  enough,  add  15  j4  grains  Ursol  D.  and 
1  oz.  hydrogen  peroxide  to  the  old  bath,  re-enter  and  proceed 
as  before. 


APPENDIX. 


METHOD  OF  COLORING  CHROME-TANNED  LEATHER. 

Wm.  M.  Norris,  of  Princeton,  N.  J.,  patented  August  10,  1897,  the 
following  process  or  method  of  coloring  leather.  The  letters  patent 
are  No.  588,000.    Mr.  Norris,  in  describing  his  improvement,  says  : 

"My  invention  consists  of  certain  improvements  in  methods  of  color- 
ing leather,  whereby  I  can  with  economy  obtain  more  even  shades  of 
color  than  usual,  and  attain  other  advantages  which  are  duly  set  forth 
hereinafter. 

"  My  process  is  especially  adapted  to  chrome-tanned  stock,  upon 
which  heretofore  it  has  been  difficult  to  produce  even  and  satisfactory 
shades  of  color,  owing  to  the  nature  of  the  tanning  materials  employed. 
The  oxide  of  chromium  formed  in  the  leather  when  this  method  of  tan- 
ning is  practiced,  does  not  supply  an  effective  base  or  mordant  for  any 
of  the  coal-tar  colors,  and  if,  as  is  likely  to  be  the  case,  some  of  the 
sulphurous  acid,  which  is  largely  employed  as  a  reducing  agent  in  the 
manufacture  of  chrome-tanned  leather,  remains  in  the  latter  in  spite  of 
the  thorough  washing  to  which  it  is  subjected,  such  sulphurous  acid  acts 
xas  a  bleaching  agent,  which  injuriously  affects  the  coloring  materials 
used  and  tends  to  prevent  the  proper  coloring  of  the  leather. 

"Heretofore  in  making  colored  leather  from  chrome-tanned  stock 
the  skins  are,  after  being  tanned  and  washed,  put  into  a  solution  of 
some  vegetable  tanning  matter,  such  as  some  bark  or  wood  extract  or 
gambier,  and  then  placed  in  another  bath  containing  some  coal  tar 
color  or  anilin.  I  find  in  the  working  of  this  process  that  owing  to  the 
conditions  referred  to  above  an  uneven,  unsatisfactory  color  is  often  the 
result,  and  that  the  vegetable  tanning  agent  employed  causes  deteriora- 
tion in  the  quality  of  the  leather.  These  difficulties  are  avoided  by  my 
improved  process,  which  is  practiced  as  follows  : 

"  In  a  reel  containing  about  six  hundred  and  fifty  gallons  of  water  I 
dissolve  three  pounds  of  permanganate  of  potash,  the  temperature  of 
the  bath  being  about  980  Fahrenheit.    Into  this  solution  I  place  about 

(  617  ) 


APPENDIX. 


one  thousand  pounds  of  stock  which  has  been  thoroughly  washed  after 
being  removed  from  the  hyposulphite  or  reducing  bath.  At  the  end  of 
half  an  hour  the  stock  should  be  removed  from  this  bath,  washed  to 
remove  any  of  the  permanganate  which  has  not  combined  with  it, 
'  struck  out,'  and  finished  in  the  usual  way.  This  treatment  alone  pro- 
duces a  yellowish-brown  color,  which  is  now  in  demand,  but  if  other 
colors  or  shades  of  color  are  desired,  the  stock,  after  being  washed  to 
remove  the  free  permanganate,  is  placed  in  a  solution  of  any  suitable 
coal-tar,  anilin,  or  other  coloring  matter,  depending  upon  the  color  de- 
sired, and  then  finished  in  the  usual  way.  Permanganate  of  potash 
destroys  any  sulphurous  acid  which  may  remain  in  the  stock  and  is 
rapidly  reduced  by  the  skins  themselves,  the  insoluble  compound  of 
manganese  formed  in  the  stock  being  of  a  yellowish-brown  color  and 
supplying  an  effective  mordant  for  other  coloring  matters  without 
altering  or  injuriously  affecting  the  quality  of  the  leather. 

"  In  order  to  impart  to  the  flesh  side  of  the  skin  the  bluish  color 
which  is  now  generally  adopted  when  the  grain  side  of  the  skin  is 
black,  the  skin  should  be  first  treated  by  the  permanganate  solution 
referred  to  above,  then  washed,  and  then  placed  in  a  drum  with  a  very 
dilute  solution  of  some  suitable  anilin,  such  as  methyl-violet.  In  this 
way  a  good  penetration  of  color  can  be  secured  and  a  good  foundation- 
color  for  the  black  formed  on  the  grain  side  of  the  skin,  there  being  no 
injury  to  the  skins  such  as  follows  the  use  of  large  quantities  of  log- 
wood and  soda,  which  are  now  employed  in  the  endeavor  to  secure  a 
penetration  of  color  on  chrome-tanned  stock. 

"  Increased  firmness  and  rigidity  of  the  leather  may  be  secured  by 
subjecting  the  skins  to  a  bath  consisting  of  a  dilute  solution  of  ferro- 
cyanide  of  potassium  (yellow  prussiate  of  potash),  say  about  five 
pounds  of  the  ferrocyanide  to  six  hundred  and  fifty  gallons  of  water, 
preparatory  to  treatment  with  the  bath  of  permanganate  of  potash,  as 
described  above. 

"  In  working  my  process  I  have  found  that  the  best  results  are  ob- 
tained by  using  the  proportions  specified,  but  I  do  not  confine  myself 
to  these  proportions,  although  in  using  such  an  article  as  permanganate 
of  potash,  which  is  a  powerful  oxidizing  agent,  dilute  solutions  only 
should  be  employed." 

ART  OF  TAWING  HIDES  OR  SKINS. 

The  specification  for  Wm.  M.  Norris'  patent  No.  588,874,  dated  Aug. 
24,  1897,  is  as  follows  : 


APPENDIX. 


619 


The  invention  relates  particularly  to  that  method  of  tawing  leather 
now  being  largely  practiced  and  known  as  "chrome"  tanning,  and  the 
object  of  the  invention  is  to  attain  greater  economy  and  other  advant- 
ages, hereinafter  particularly  pointed  out,  in  the  practice  of  said  method. 

The  "beam-work"  of  my  improved  process  is  substantially  the  same 
as  the  beam-work  in  chrome  tannage  as  at  present  ordinarily  practiced, 
and  the  tanning  is  substantially  the  same,  with  the  exception  that  in  my 
improved  process  I  provide  for  a  continuous  evolution  of  nascent  hydro- 
gen in  the  second  or  reducing  bath.  This  nascent  hydrogen  operates  to 
change  the  thiosulphuric  acid  or  the  sulphurous  acid  present  or  liber- 
ated in  said  bath  into  hyposulphurous  acid,  which  is  a  more  powerful 
reducing  agent  and  possesses  other  advantages,  hereinafter  referred  to. 

By  the  term  "  hyposulphurous  acid  "  as  used  in  this  description  I 
mean  not  the  compound  which  has  been  some  time  so  called,  and  which 
is  otherwise  and  more  properly  known  as  "thiosulphuric  acid,"  but  the 
compound  expressed  by  the  symbol  rTSO,  or  H.,S204,  and  known  also 
as  "hydrosulphurous  acid." 

I  first  tan  or  taw  the  hides  or  skins  by  subjecting  them,  as  heretofore 
practiced,  to  bichromate  of  potash  or  analogous  salt,  such  as  bichromate 
of  soda,  dissolved  in  water,  to  which  an  acid,  such  as  hydrochloric  acid, 
is  added,  taking,  say,  for  each  one  hundred  pounds  of  raw  hides  or  skins 
about  five  pounds  of  bichromate  of  potash  or  its  equivalent  and  two  and 
one-half  pounds  of  hydrochloric  acid  of  21°  Baume  or  an  equivalent 
amount  of  sulphuric  acid,  the  amount  of  water  in  the  bath  being  suffi- 
cient to  properly  cover  the  skins.  The  hides  or  skins  having  been  left 
in  this  bath  until  thoroughly  impregnated  with  the  chromium  compound 
are  then  removed,  pressed  or  "struck  out"  to  remove  surplus  liquor, 
when  the  stock  is  ready  for  the  reducing  bath. 

So  far  my  improved  process  does  not  depart  from  the  process  of 
chrome  tanning  as  now  ordinarily  practiced,  but  in  the  present  practice 
of  chrome  tanning,  as  known  to  me,  the  second  or  reducing  bath  con- 
sists, ordinarily,  of  hyposulphite  of  soda,  by  which  I  mean  the  compound 
Na.:S20:„  more  correctly  designated  as  "sodium  thiosulphate,"  and  hy- 
drochloric acid  in  water.  The  thiosulphuric  acid  liberated  by  the 
action  of  the  hydrochloric  acid  upon  the  hyposulphite  of  soda  in  this 
ordinary  reducing  bath  is  very  unstable,  and  is  resolved  almost  as  rapidly 
as  generated  into  sulphurous  acid  and  sulphur,  this  action  being  so 
quick  and  energetic  as  to  be  easily  observable.  The  active  agent, 
therefore,  in  this  bath  is  sulphurous  acid,  with  which  the  hides  or  skins 


620 


APPENDIX. 


become  impregnated,  while  sulphur  is  thickly  deposited  in  the  fibres  on 
the  grain  and  flesh  sides  of  the  hides  or  skins.  To  free  the  latter  from 
the  sulphurous  acid  and  sulphur  requires  a  thorough  washing,  which 
usually  takes  considerable  time  and  requires  the  use  of  a  number  of  reels 
or  other  apparatus,  which  might  be  otherwise  more  advantageously 
utilized,  consumes,  furthermore,  much  water,  and  is  sometimes  injurious 
to  the  leather.  To  overcome  these  objections  to  the  now  commonly 
employed  reducing  bath,  I  add  to  said  bath  metallic  zinc,  whereby 
there  is  continuously  liberated  in  the  bath  nascent  hydrogen,  which 
operates  to  convert  sulphurous  acid,  when  formed,  into  hyposulphurous 
acid,  the  reaction  being  expressed  by  the  equation 

2H2S03+H2=H2SA+2H20, 

or,  as  it  is  stated  in  other  books  on  chemistry, 

H2S03+H2==H2S02+H20, 

and,  doubtless,  it  operates  also  to  lessen  or  prevent  the  formation  of 
sulphurous  acid  by  converting  the  thiosulphuric  acid  produced  by  the 
action  of  the  hydrochloric  acid  upon  the  hyposulphite  of  soda  directly 
into  hyposulphurous  acid. 

The  method  which  I  prefer  for  the  development  or  liberation  of  the 
nascent  hydrogen  is  the  very  simple  and  economical  method  of  placing 
a  number  of  pieces  of  metallic  zinc  in  the  vessel  containing  the  bath, 
these  pieces  being,  where  a  reel  is  employed,  sufficiently  large  and 
heavy  to  remain  at  the  bottom  of  the  bath  without  being  disturbed  by 
the  motions  of  the  liquor  caused  by  the  paddles  in  the  reel.  The  bath 
being  acid,  a  continuous  liberation  of  nascent  hydrogen  from  the  me- 
tallic zinc  will  take  place,  but  I  wish  it  understood  that  I  do  not  confine 
myself  to  this  particular  method  of  evolving  nascent  hydrogen  in  the 
bath,  as  other  modes  may  be  employed. 

I  have  found  the  following  to  be  an  efficient  reducing  bath  made  in 
accordance  with  my  invention,  although  it  will  be  understood  that  the 
proportions  specified  may  be  departed  from  without  departing  from  the 
invention.  For  the  treatment  of,  say,  one  thousand  pounds  of  skins,  a 
bath  of  125  pounds  of  hyposulphite  of  soda  and  50  pounds  of  muriatic 
acid  in  650  gallons  of  water  is  prepared,  and  to  this  bath  is  added  60 
pounds  of  metallic  zinc.  The  zinc  should  be  allowed  to  remain  when 
the  liquor  is  drawn  off  after  the  bath  is  exhausted  and  a  new  bath  is 
prepared,  and  about  5  pounds  of  metallic  zinc  should  be  added  about 
once  a  week. 


APPENDIX. 


Instead  of  having  pieces  of  zinc  at  the  bottom  of  the  reel,  the  latter 
may  be  lined  with  sheet  zinc,  thus  exposing  a  large  surface  to  the  action 
of  the  acid  solution. 

Some  manufacturers  for  their  reducing  or  second  bath  use  instead  of 
hyposulphite  of  soda  and  acid,  a  solution  of  what  is  commercially 
known  as  "bisulphite  of  soda,"  prepared  for  this  purpose.  This  I 
understand  to  be  an  aqueous  solution  of  sulphite  of  soda  saturated  with 
sulphurous  acid  gas,  and  the  bath  may  be  the  same  as  before  given, 
except  that  the  acid  is  omitted  and  the  hyposulphite  of  soda  is  replaced 
by  an  equal  number  of  pounds  of  the  bisulphite  solution.  In  this  case 
the  zinc  is  used  in  substantially  the  same  way  as  formerly  described  in 
connection  with  the  reducing  bath  of  hyposulphite  of  soda  and  muriatic 
acid.  Although  no  sulphur  is  developed  in  such  a  solution,  the  libera- 
tion of  nascent  hydrogen  in  such  a  bath  would  convert  the  sulphurous 
acid  into  hyposulphurous  acid,  which  would  be  an  advantage,  and  much 
less  bisulphite  would  be  required.  Hence,  my  invention  is  applicable 
to  a  bath  of  this  character,  and  is  so  claimed. 

Nascent  hydrogen  acting  upon  a  solution  of  bisulphite  of  soda  gives 
rise  to  the  reactions  which  are  expressed  by  these  equations  : 

4NaHS03+HJ=H2S,04+2Na2S03+2H,0, 

or 

2NaHS03+H.2=H2SO,f  Na2SOa+H20. 

It  is  customary  after  skins  are  taken  from  the  first  or  chrome  bath 
and  struck  out  to  dip  them  each  singly  into  a  dilute  solution  of  hypo- 
sulphite of  soda,  to  which  muriatic  acid  is  added,  this  treatment  being 
for  the  purpose  of  bringing  the  stock  into  the  best  condition  for  the 
reducing  bath,  and  for  effecting  a  slight  surface  reduction,  which  acts 
to  prevent  the  washing  out  of  the  chromium  compound  from  the 
stock  when  placed  in  the  reducing  bath. 

A  zinc-lined  vessel  may  be  advantageously  used  to  contain  the  solu- 
tion into  which  the  stock  is  thus  dipped,  or  pieces  of  zinc  may  be 
added  to  the  solution,  as  the  nascent  hydrogen  which  will  thus  be  de- 
veloped will  increase  the  efficacy  of  the  solution,  less  hyposulphite  of 
soda  will  be  required,  and  less  sulphur  will  be  developed. 

The  results  of  my  improvement  are  : 

First.  A  comparatively  small  amount  of  sulphur  is  liberated  and  little 
or  no  sulphurous  acid  brought  into  contact  with  the  skins  or  hides,  so 
that  when  the  latter  are  taken  from  the  reducing  bath  very  little  wash- 


622 


APPENDIX. 


ing  is  necessary  to  perfectly  cleanse  them  and  make  them  quite  neutral 
and  in  good  condition  for  the  subsequent  finishing  operations,  and  in 
this  way  material  economies  of  time,  labor  and  apparatus  are  gained. 

Second.  Hyposulphurous  acid  being  a  much  more  powerful  reducing 
agent  than  sulphurous  acid,  the  quantity  of  hyposulphite  of  soda  requi- 
site for  the  reducing  bath  is  by  my  improvement  materially  reduced. 
About  one-half  of  the  quantity  of  hyposulphite  of  soda  heretofore  con- 
sidered necessary  will  in  my  improved  process  suffice — that  is  to  say, 
where  20  per  cent,  of  the  weight  of  the  skins  of  hyposulphite  of  soda 
and  5  per  cent,  of  the  weight  of  the  skins  of  muriatic  acid  have  been 
used  heretofore,  10  per  cent,  of  hyposulphite  of  soda  and  5  per  cent, 
of  muriatic  acid  will  be  sufficient  when  my  improved  process  is 
employed. 

BORAX. 

Tanners  and  curriers  fully  realize  that  soft  water  is  a  great  aid  in 
making  good  leather.  Some  of  the  most  beautiful  leather  in  the  world 
comes  from  Denmark.  In  that  country  spring  water  is  a  great  rarity, 
and  the  many  small  streams  and  lakes  are  fed  mainly  by  rain  water  ;  the 
water  is  very  soft,  and  particularly  well  adapted  for  the  production  from 
raw  material  treated  with  it  of  a  pliable  leather  of  most  excellent  feel. 

The  waters  of  the  United  States  vary  greatly  in  their  hardness,  and 
many  a  tanner  has  failed  in  business  because  there  was  a  leak  in  his 
tannery  which  he  could  never  find,  search  as  he  would,  and  this  leak 
was  constant  in  its  working,  never  ceasing,  eating  his  profits  away,  eat- 
ing up  his  hides  and  skins,  eating  up  his  bark  pile,  eating  up  his  dye 
stuffs,  and  in  the  end  ruining  him  beyond  repair.  This  leak  worked  in 
the  day  time,  in  the  twilight,  in  the  night,  on  Sundays  and  on  all  other 
holidays,  constantly  the  same.    This  leak  was  hard  water. 

There  is  no  necessity  for  any  tanner,  or  currier,  or  leather  dyer  to 
work  with  hard  water,  as  one  of  the  best  water  softeners  in  the  world  is 
now  within  his  reach  at  a  low  cost.  We  refer  to  borax,  which  can  now 
be  bought  for  about  5^30.  per  lb.  ;  and  5  lbs.  of  borax  will  soften  1,000 
gallons  of  water  and  render  it  fit  for  the  soaks,  the  leaches,  or  the  dye 
house.  It  is  best  to  first  dissolve  it  in  boiling  water  and  then  add  the 
water  to  be  used  under  constant  stirring. 

Borax  is  also  one  of  the  best  known  agents  for  whitening  or  bleach- 
ing leather  of  all  kinds.  Every  known  variety  of  russet  leather  is 
bleached  with  borax  and  sulphuric  acid.  After  this  variety  of  leather 
is  shaved,  it  is  put  into  a  pin-wheel  with  a  solution  of  borax,  2  pounds 


APPENDIX. 


623 


to  100  gallons  of  water,  and  washed  thoroughly.  While  it  is  still  in  the 
wheel,  it  receives  a  bath  of  weak  sulphuric  acid  to  neutralize  the  alkali, 
and,  at  the  same  time,  take  out  any  iron  stains  that  may  be  in  the 
leather.  The  borax  bath  is  drawn  off  before  the  sulphuric  acid  bath  is 
applied.  The  borax  bath  works  out  the  dirt  and  makes  the  leather 
appear  much  darker.  The  sulphuric  acid  bath  changes  the  color  of  the 
leather  to  a  much  lighter  shade  than  it  was  originally. 

This  is  one  of  the  secrets  of  the  chrome  process  of  tanning  kid. 
Some  manufacturers  make  their  kid  of  a  nice  white  color,  and  all  of  the 
other  manufacturers  are  wondering  how  they  do  it.  The  above  process 
of  bleaching  or  whitening  the  leather  with  borax  and  sulphuric  acid 
explains  it.  In  kid  some  makers  after  the  sulphuric  acid  bath  is  drawn 
off,  give  the  leather  a  hot  bath  of  Sicily  sumac  and  alum,  which  imparts 
a  still  lighter  shade,  and  at  the  same  time  softens  it.  The  kid  is  then 
rinsed  in  clear  water  in  a  tank,  and  is  immediately  struck  out  to  remove 
the  water  and  surplus  sumac.  The  leather  is  now  ready  to  be  dyed  or 
colored.  Then,  again,  the  working  of  the  dirt  out  of  the  hide  or  skin 
by  the  aid  of  borax  before  placing  it  in  the  tanning  liquor,  be  the  liquor 
vegetable  or  mineral,  is  a  great  help  to  rapid  tannage,  as  it  is  well 
known  that  the  cleaner  a  hide  or  skin  is,  when  it  is  placed  in  the  liquor, 
the  quicker  it  can  be  tanned.  Borax  is  one  of  the  gentlest  of  the  alka- 
lies ;  but  it  is  the  mortal  foe  of  dirt.  It  utterly  destroys  it,  and  that  is 
the  secret  why  all  the  laundries  in  the  country  use  borax  to  soften  the 
water  in  which  they  soak  or  wash  the  clothes  to  be  laundered. 

Borax  is  also  one  of  the  greatest  preservatives  known.  All  the  larger 
packers  of  the  country  are  using  it  to  preserve  their  meats,  and  it  is  also 
being  used  as  a  preservative  for  hides  and  skins  in  the  place  of  salt.  It 
leaves  no  salt  stains,  and  hides  or  skins  preserved  with  borax  are  there- 
fore worth  more  than  those  preserved  with  salt. 

In  the  making  of  "  sig"  stains,  blacks  and  pastes  for  leather,  borax 
is  the  currier's  friend ;  if  the  water  is  hard  it  is  not  good  for  these  pur- 
poses, but  a  little  borax  softens  the  water  and  makes  it  fit  for  use.  The 
same  is  true  of  the  finishes.  No  other  agent  will  cut  the  shellac  used 
and  soften  the  water  so  well  as  borax.  It  is  also  one  of  the  best  known 
agents  in  the  preparation  of  blood  and  egg  albumen,  and  is  equally 
good  in  the  preparation  and  preservation  of  egg  yolk,  so  much  used  by 
makers  of  kid  and  glove  leather. 

Borax  has  been  used  in  the  leather  industry  for  more  than  fifty  years, 
each  year  extending  its  use,  until  now  no  tanner,  currier  or  leather  dyer 


624 


APPENDIX. 


can  afford  to  be  without  it.  He  must  keep  it  on  hand  the  same  as  he 
does  his  bark  or  his  hides  or  skins,  in  large  or  small  quantities,  accord- 
ing to  his  uses  for  it,  and  they  are  many  about  a  tannery  or  currying 
shop. 

One  reason  of  the  growing  use  of  borax  is  its  steady  fall  in  price  dur- 
ing the  past  fifty  years  from  76  cents  a  pound  in  1847  to  5^  cents  a 
pound  in  1897,  one-fifteenth  of  its  cost  fifty  years  ago. 

The  following  table  shows  the  range  of  the  average  New  York  whole- 
sale price  of  borax  during  the  past  fifty  years  : 

Cts.  C/s.  Cts. 

1847  per  lb. .76  1864  per  lb. .39  1881  perlb..i3% 

1848  72  1865  yj%  1882  13% 

1849  70  1866  33  1883  14% 

1850  681-2  1867  353^  1884   9% 

1851  67J4  1868  33I3  1885   %% 

1852  66  1869  35  1886   6% 

1853  65  1870  30^  1887   5% 

1854  64i.2  1871  31 1-4  1888   7 

1855  6o>2  1872  32  1889   7>£ 

18S6  57  l873   244  1890   i% 

1857  S6H  l874   Hi  1891    7^ 

1858  54  1875  12%  1892   7% 

1859  50  1876  io7g  1893   7% 

i860  48  1877   9%  1894   7 

1861  45  1878   8%  1895  

1862  42  1879   9  1896   5^ 

1863  40        1880   I2>4    1897   S>2 

Borax,  in  addition  to  its  many  other  uses  in  the  currying  shop,  is  also 
employed  for  cutting  the  oils  and  fats  used  in  stuffing  leather,  it  having 
displaced  sal  soda,  chip  soap,  soapine  and  all  other  alkalies  for  this  pur- 
pose. Borax  is  also  used  in  the  best  known  mordants  for  colored  leathers. 
It  "  bites"  or  mordants  the  hides  or  skins  uniformly,  and  is  not  harsh 
in  its  action,  because  it  is  so  gentle  an  alkali.  This  is  the  chief  cause  of 
its  popularity  with  the  leather  dyer.  This  gentleness  makes  its  value  in 
the  kid  industry  to  neutralize  the  excess  of  fat  liquor  and  to  wash  all 
leather  tanned  by  the  chrome  process,  this  washing  giving  a  more  uni- 
form color  and  lustre  to  the  skins  after  coloring  or  dyeing.  A  recent 
writer  has  truly  said  that  it  is  not  easy  to  convince  any  old  tradesman 
that  a  better  mode  can  be  found  than  the  one  he  has  practiced  all  his 
life  and  all  his  ancestors  before  him.  Some  tanners  have  quoted  the 
maxim,  "leave  well  enough  alone,"  adding,  "we  have  done  so  well  by 


APPENDIX. 


625 


the  old  mode,  we  shall  not  make  any  change."  But  you  will  have  to 
make  a  change.  Modern  business  is  done  on  a  different  plane  from  the 
business  of  the  past.  It  is  now  truly  a  fight,  a  battle  in  fact — the 
fighting  is  done  with  the  brain — and  the  man  who  survives  is  the  one 
who  watches  to  see  if  any  economy  can  be  practiced  or  any  saving  be 
made  in  any  of  the  departments  of  his  tannery  or  currying  shop. 

A  most  important  use  of  borax  in  the  tanning  trade  is  its  employ- 
ment in  softening  the  water  for  its  soaks,  cleansing  and  preserving  the 
hides  and  skins  and  preventing  the  withdrawing  of  their  gelatine,  thus 
making  heavier,  more  solid  and  more  salable  leather. 

There  are  two  reasons  why  the  tanners  of  all  kinds  of  hides  and  skins 
should  use  it  in  their  soaks,  as  the  soaks  are  always  kept  fresh  and  pre- 
vented from  becoming  putrid  or  foul,  and  thus  withdrawing  valuable 
gelatine  from  the  hide  or  skin  under  treatment.  Borax  can  be  used 
not  only  in  the  soaks,  but  in  the  limes  and  bates  as  well.  Its  antiseptic 
qualities  keep  all  of  these  liquors  fresh  and  sweet.  It  renders  water 
beautifully  clear,  sweet  and  soft,  and  just  in  the  right  condition  for  the 
soaks,  just  right  for  the  leaches,  for  scouring  and  for  the  final  cleansing  of 
the  hide  or  skin  preparatory  to  placing  it  in  the  tanning  liquor.  Borax 
removes  all  taint,  dry  rot  or  decomposition  from  the  hide  or  skin,  and 
all  other  unhealthy  changes,  and  produces  a  leather  which  will  repay 
the  tanner  or  currier  ten  times  over  for  its  use.  It  kills  the  bacilli  of 
anthrax  when  used  in  the  soaks,  as  it  thoroughly  disinfects  the  hide  or 
skin,  which  is  exposed  to  its  action.  We  will  speak  of  anthrax  later  on. 
Borax  can  be  used  in  all  climates  and  in  all  waters,  hard,  soft  or  sea 
water,  and  will  instantly  destroy  all  unhealthy  and  infectious  germs 
wherever  located,  and  in  whatever  part  of  the  hide,  skin  or  tanning  ma- 
terial they  may  be.  It  will  remove  all  dirt  quickly,  as  it  is  one  of  the 
most  perfect  of  cleansers,  and  will  prepare  the  hide  or  skin  for  the 
reception  of  the  tanning  liquor  more  thoroughly  than  any  other  agent. 
In  the  rinsing  or  cleansing  of  the  hide  or  skin  preparatory  to  placing  it 
in  the  tanning  liquor,  borax  will  be  found  to  be  the  cheapest,  most 
harmless  and  most  efficient  of  the  cleansing  agents.  In  the  leaches, 
borax  will  be  found  to  be  a  very  efficient  agent  for  softening  the  water, 
as  hard  water  has  to  have  its  hardness  overcome  by  the  tannic  acid  in 
the  bark  before  it  can  become  efficient  for  leaching  the  bark.  Caustic- 
soda  and  similar  chemicals  may  be  used  for  softening  water ;  they  are 
cheaper  than  borax,  but  will  not  do  the  work  so  efficiently,  as  they  all 
withdraw  the  gelatine  from  the  skin  or  hide,  and  thus  make  a  soft  and 
40 


626 


APPENDIX. 


less  salable  leather.  Borax  is,  therefore,  a  cheap  agent.  The  antisep- 
tic qualities  of  borax  preserve  the  liquors  and  keep  them  fresh  and 
sweet,  and  at  the  same  time,  it  being  an  alkali,  very  gentle  fermenta- 
tion of  the  bark  is  caused,  so  as  fully  to  extract  the  tannin  and  to  allow 
it  to  enter  into  combination  with  the  hide  or  skin  without  becoming 
crystallized.  It  is  this  fact  which  makes  borax  so  valuable  for  soften- 
ing water  for  leaching  tan  bark.  Borax  is  the  material  which  is  de- 
pended upon  in  nearly  all  the  so-called  quick  tanning  processes  to  do 
the  work  in  aiding  the  penetration  of  the  tannin.  It  improves  and  at  the 
same  time  cheapens  all  leather  produced.  Leather  is  made  in  the  beam 
house — not  in  the  tanyard.  If  you  lose  the  gelatine  in  the  soaks,  limes 
or  bates  it  can  never  afterward  be  replaced  in  the  hide  or  skin,  and  the 
result  of  tanning  will  only  be  an  inferior  leather.  Borax  stands  alone 
in  its  antiseptic,  decay-arresting,  purifying  attributes.  Tanning  belongs 
to  those  industries  in  which  the  decomposition  of  organic  materials  by 
micro-organisms  plays  an  important  role.  The  following  recognized 
putrefactive  ferments  have  been  met  with  in  tan  liquors  :  Bacillus  fluor- 
escens  liquefaciens  (Flugge)  ;  B.  megatherium  (De  Bary)  ;  B.  subtilis 
(Ehrenberg)  ;  potato  bacillus;  B.  mesentericus  fuscus  (Flugge)  ;  B. 
mycoides  (Flugge)  ;  B.  viscosis  (Frankland)  ;  gas-forming  bacillus 
(Eisenberg)  ;  white  bacillus  (Maschek)  j  proteus  vulgaris,  proteus  mira- 
bilis  (Hauser)  ;  Bacillus  butyricus  (Hueppe);  white  streptococcus 
(Maschek);  worm-shaped  streptococcus  (Maschek);  chey  coccus 
(Maschek).  Besides  these  known  species  there  are  other  yet  unde- 
scribed,  but  putrefactive  organisms,  most  of  which  have  a  similar  effect 
on  the  subsequent  fermentation.  They  naturally  occur  most  numer- 
ously in  the  weak  liquor.  As  an  example  of  the  way  certain  bacteria 
get  into  a  tannery,  the  following  is  given  :  The  waste  water  of  a  large 
works  discharged  into  a  neighboring  river  was  found  to  contain  large 
numbers  of  proteus  vulgaris  and  B.  fluorescens  liquefaciens ;  the  same 
bacteria  were  found  not  only  in  the  water,  but  in  the  limes  and  tan 
liquors  of  a  tannery  a  mile  down  stream,  drawing  its  waters  from  the 
same  river.  Where  the  cold-sweat  process  of  unhairing  is  used  a  still 
larger  number  of  putrefactive  organisms  are  found  in  the  liquors. 
Oak-wood  and  quebracho  extracts,  which  ferment  with  difficulty,  owing 
to  a  lack  of  suitable  nutrient  material,  are  good  growing  ground  for 
molds.  Their  special  function  is  the  decomposition  of  tannins  of  a 
glucoside  character.  It  will  be  seen  from  the  above  mentioned  organ- 
isms that  the  souring  of  the  tan  liquors  is  influenced  by  numerous  fac- 


APPENDIX. 


tors,  and  is  no  regular  fermentation,  such  as  alcoholic  or  acetic  acid 
fermentation.  A  bacteriological  examination  of  the  liquors  has  shown 
a  whole  series  of  bacteria  and  fungi  in  the  liquors,  but  chemical  analysis 
shows  the  following  to  be  the  chief  products  :  Carbonic  acids,  ethyl 
alcohol,  acetic  acid  and  lactic  acid.  Although  all  these  are  of  equal 
theoretical  importance,  only  the  two  latter  are  to  be  considered,  and  the 
bacteriological  research  is  much  simplified  by  considering  only  those 
species  which  produce  these  two  acids.  Of  the  two,  lactic  swells  the 
skin  better  than  acetic  acid.  The  chemist  who  made  this  examination 
in  Germany  found  no  organism  in  tan  liquors  capable  of  fermenting  glu- 
cose direct  to  acetic  acid,  and  he  considers  that  the  production  of  this 
acid  in  the  liquors  is  the  result  of  two  distinct  processes  :  (  i )  the  for- 
mation of  alcohol ;  (  2)  the  oxidation  of  the  alcohol  to  acetic  acid  ;  that 
lactic  and  acetic  acids  are  the  result  of  entirely  different  chemical  pro- 
cesses, and  are  produced  by  different  organisms.  The  present  genera- 
tion need  fear  no  scarcity  of  hemlock  or  oak  bark.  The  question  of 
the  day  in  the  struggle  for  economical  results  in  the  tanning  industry  is 
leaching.  Many  tanners  delude  themselves  with  the  idea  that  they  are 
getting  the  best  results  possible  considering  the  conditions  under  which 
they  are  working,  and  by  an  occasional  analysis  of  their  spent  tan  they 
apparently  prove  their  position.  The  results  to  be  obtained  it  must  be 
admitted  consist  in  the  extraction  of  a  maximum  amount  of  tannin  with 
a  minimum  amount  of  water.  If  the  water  is  hard  it  will  take  more  of  it 
to  do  the  leaching  than  if  it  is  soft.  Borax  softens  the  water  and  allows 
it  to  take  immediate  hold  of  the  tan  bark.  What  we  must  seek  to  do  in 
leaching  is  to  pass  the  water  through  the  bark  and  not  around  it.  Water 
which  has  been  softened  with  borax  is  more  penetrating,  when  either 
hot  or  cold,  than  is  water  which  has  not  been  softened.  In  this  coun- 
try, in  the  leaching  of  oak  bark,  hemlock  bark,  canaigre  and  other  tan- 
nins, hot  water  is  generally  employed.  The  temperature  at  which  it 
goes  on  the  head-leach  is  not  material ;  anywhere  from  ioo°  to  140°  F. 
will  do,  but  its  temperature  should  be  gradually  increased  until  the  water 
is  at  the  boiling  point  on  the  tail-leach.  Only  in  this  way  can  the  max- 
imum amount  of  tannin  be  obtained.  The  antiseptic  qualities  of  borax 
preserve  the  bark  liquors  and  keep  them  fresh.  The  word  antiseptic  is 
derived  from  anti  (against),  septikos  (putrescency).  As  an  antiseptic, 
borax  stands  pre-eminent,  and  may  therefore  well  take  the  place  of  car- 
bolic acid,  vitriol,  chloride  of  lime,  creosote  and  arsenic,  wherever  em- 
ployed.   We  do  not  care  whether  you  depilate  with  lime,  sulphide  of 


628 


APPENDIX. 


sodium  or  any  other  agent,  either  sole,  belting,  harness  or  upper  leather 
of  any  kind,  whether  it  is  produced  from  hides  or  skins,  it  is  necessary 
that  the  hide  or  skin  should  be  clean  before  it  is  placed  in  the  tan 
liquor.  Sour  liquor  will  not  then  be  required  to  overcome  the  depilitant. 
Then  feed  the  hide  or  skin  regularly ;  do  not  check  it  with  too  much 
liquor  or  too  strong  a  liquor,  or  starve  it  by  withholding  supplies.  Re- 
member that  there  is  no  vacuum  of  time  when  the  hide  or  skin  is  not 
feeding.  If  it  is  not  fed  continuously  it  will  exude  and  lose  its  gela- 
tinous matter,  and  this  matter,  once  lost,  can  never  be  recovered  or  re- 
placed. Borax  is  the  only  substance  which  will  properly  prepare  the 
hide  or  skin  for  the  reception  of  the  tannin  liquor.  Then,  too,  borax  is 
one  of  the  best  agents  for  softening  water  to  be  used  on  hides  and  skins 
preparatory  to  stuffing.  To  obtain  a  fine  grain  color  the  leather  must 
be  moistened,  and  must  contain  a  certain  amount  of  water  when  the  oil 
or  fat  is  put  on,  so  as  to  resist  the  penetrating  properties  of  the  oil  or 
fat,  which  can  only  be  absorbed  as  the  water  is  slowly  evaporated.  Do 
not  make  the  mistake  of  greasing  the  hide  or  skin  on  both  sides  ;  this 
will  prevent  the  evaporation  of  the  water  and  the  penetration  ot  the  oil 
or  fat.  Water  which  has  been  softened  with  borax  has  just  a  trace  of 
this  alkali  in  it,  but  enough  to  assist  the  penetration  of  the  oil  or  fat. 
This  applies  to  both  hand  and  drum  stuffing.  In  dyeing  leather,  the 
use  of  soft,  bright,  clear  water  permits  of  the  getting  of  good  colors, 
particularly  when  there  are  bright  shades.  In  fact,  where  any  alkali  is 
now  employed  in  the  tannery  or  currying  shop,  it  will  be  found  that 
borax  will  take  its  place  and  will  give  more  satisfactory  results  and 
better  leather.  The  harness  leather  men  and  fancy  leather  manu- 
facturers, and,  in  fact,  all  makers  of  leather,  are  already  using  borax 
extensively,  and  now  it  is  so  cheap  as  to  be  within  the  reach  of  all 
leather  producers.  For  grain,  split,  buffed,  patent,  enamel,  furniture, 
in  fact,  any  leather  which  requires  a  smooth  split,  there  is  no  agent 
as  good  as  borax,  to  be  used  in  dampening  before  splitting.  The  use 
of  boracic  acid  as  a  tbate  for  chrome  tanned  has  been  explained  on 
page  335,  and  hence  needs  no  special  description  here.  Borax  is 
largely  used  in  the  process  of  chrome  tannage  for  washing  the  hides  and 
skins  after  they  come  from  the  chrome  liquor.  They  should  then  be 
well  washed  in  warm  water,  then  in  i  to  ij^  per  cent,  of  borax  solu- 
tion, and  finally  again  in  water.  They  are  then  ready  to  be  fat  liquored, 
stained,  colored,  set  out,  oiled  off,  etc.,  and  finished. 


APPENDIX. 


629 


ANTHRAX. 

Acting  upon  the  request  of  the  Secretary  of  Agriculture,  the  Treasury 
Department  has  requested  the  Secretary  of  State  to  instruct  all  consular 
officers  of  the  United  States  to  refuse  authentication  of  invoices  of 
hides  of  meat  cattle  from  districts  in  which  anthrax  exists.  This  re- 
quest is  made  in  view  of  the  fact  that  a  number  of  deaths  of  human 
beings  and  cattle  recently  occurred  at  Falls  Creek,  Pa.,  in  consequence 
of  the  manipulation  of  hides  in  tanneries  at  that  place. 

Much  apprehension  has  been  awakened  in  the  United  States  during 
the  past  few  years  by  the  supposed  appearance  of  anthrax.  Anthrax 
in  its  most  malignant  form  exists  in  the  countries  of  southern  Europe 
and  the  Orient.  Cattle,  sheep,  goats,  and  once  in  a  while  the  horse,  are 
attacked  by  the  disease,  which  manifests  itself  as  a  splenic  fever  in 
those  animals. 

Unfortunately,  the  disease  is  easily  conveyed  to  man  in  any  climate, 
but  only  through  inoculation.  The  medium  through  which  man  may 
be  afflicted  is  the  hair,  wool  or  hides  of  any  animal  which  has  died  of 
the  disease,  tf  a  man's  hand  should  have  an  abrasion  and  he  should 
be  among  infected  hides,  the  specific  bacillus  of  anthrax  may  inoculate 
him  where  the  abrasion  is.  In  man  its  manifestation  is  variously  de- 
scribed as  malignant  pustule,  contagious  carbuncle,  wool  sorters'  and 
hair  combers'  disease. 

It  is  therefore  known  in  the  human  subject  as  a  "wound  disease." 
Unless  the  treatment  is  speedy  the  inoculation  is  rapidly  followed  by  a 
virulent  form  of  local  inflammation,  attended  with  sloughing  and  speedy 
systematic  poisoning.  The  dust  of  infected  wool  or  hair  invades  the 
throat  and  windpipe  in  wool  sorters'  disease,  causing  inflammation, 
poisoning  all  the  surrounding  tissues,  and  ending  life  by  most  distress- 
ing symptoms.  After  the  inoculation  there  is  great  prostration,  and 
death  follows  in  a  day  or  two  from  exhaustion. 

Naturally,  health  boards  of  seaport  cities  are  anxious  to  have  a 
thorough  inspection  of  all  hides,  wool  and  hair  imported.  There  are 
very  rare  instances  of  anthrax  in  New  York  City,  but  it  will  be  found  on 
the  records  of  the  hospitals  that  there  are  perhaps  a  half  dozen  cases 
every  year. 

The  New  York  City  health  authorities  have  been  on  their  guard,  and 
there  is  a  constant  inspection  of  incoming  hides,  hair  and  wool. 
President  Wilson,  of  the  Health  Board,  says  that  there  is  no  ground  for 
fear  of  anthrax  because  of  its  supposed  appearance  in  other  parts  of 


630 


APPENDIX. 


the  country.  On  the  subject  of  anthrax  Dr.  H.  M.  Biggs,  the  chief 
bacteriologist  of  New  York  city,  says  : 

"In  the  human  subject  the  disease  is  not  necessarily  fatal.  If  there 
is  a  rapid  treatment  after  inoculation  the  patient  generally  recovers. 
The  treatment  is  excision  or  the  cutting  out  of  the  diseased  flesh. 
There  are  few  cases,  and  the  element  of  danger  is  extremely  small. 

"  There  are  no  marked  external  indications  of  the  disease  in  cattle. 
Once  started,  it  may  go  through  whole  pastures." 

Among  the  earliest  of  Pasteur's  works  was  the  preparation  of  an  an- 
thrax vaccine  to  prevent  the  spread  of  the  disease  in  animals.  The 
vaccination  has  resulted  in  an  inestimable  amount  of  benefit,  and  the 
human  race  has  been  saved  from  a  serious  danger.  It  is  one  of  the 
monuments  to  the  name  of  Pasteur. 

The  disease  in  cattle  may  originate  in  the  food.  The  bacillus  is  most 
persistent.  There  is  no  time  limit  to  its  existence  in  hides,  hair  and 
wool.    It  will  offer  danger  for  years. 

The  spores  of  the  bacilli  are  used  as  tests  for  disinfectants,  and,  as  has 
been  previously  stated,  borax,  when  used  as  a  preservative  for  the  hides 
and  skins,  or  in  the  soaks,  will  kill  them. 

DEGRAS. 

Degras,  the  kind  made  from  wool  washing,  not  the  French  degras,  is 
used  in  finishing  three-quarters  of  the  American  finished  upper  leather, 
of  which  nearly  $9,000,000  worth  was  exported  from  the  United  States 
in  1896.  This  export  business  is  rapidly  increasing.  Degras  imparts 
peculiar  qualities  to  the  leather  that  no  other  greases  and  no  oils  can 
give ;  in  fact,  after  the  hide  and  bark,  it  is  the  principal  article  used  in 
the  manufacture  of  upper  leather.  Some  tanners  have  tried  to  substi- 
tute menhaden  oil  for  degras,  but  with  only  poor  results. 

The  manufacturer  of  good  upper  leather  can  not  afford  to  use  men- 
haden oil  at  any  price,  as  it  contains  a  gummy  substance  that  is  likely 
to  fry  out  when  the  leather  has  been  finished  a  short  time.  This  in  ex- 
port leather  would  be  fatal.  In  the  old  days,  when  "  anything  was  good 
enough  for  leather,"  menhaden  oil  was  used,  but  with  only  disastrous 
effects,  as  the  oil  became  gummy,  and,  when  the  leather  was  rolled  up 
for  a  little  while,  the  rolls  could  not  be  opened  because  the  sides  were 
so  stuck  together  by  this  gum  or  fish  glue.  The  leather  manufacturer 
who  would  go  back  to  menhaden  oil  would  ignore  the  improvements 
which  have  been  made  in  his  craft  during  the  past  twenty-five  years. 


APPENDIX. 


631 


The  Japan  fish  oil,  which  is  being  used  to  some  extent,  we  are  in- 
formed, is  not  like  cod  oil  made  from  livers,  but  is  similar  to  menhaden 
oil,  a  product  of  pressing  the  whole  fish  ;  and  hence,  when  it  is  used 
for  leather,  the  leather  will  gum  or  stick  together  when  rolled  similar  to 
menhaden  oil,  the  only  difference  being  that  the  Japan  fish  oil  takes  a 
little  longer  time  to  stick  the  leather  together,  probably  from  having 
less  fish-glue  in  it. 

AMERICAN  DEGRAS  FROM  WOOL  WASTE. 

Real  degras  is  the  oxidized  fish  oil  wrung  from  chamois  skins  during 
the  process  of  tannage,  and  it  is  imported  from  France.  An  imitation 
degras  is  made  from  wool  waste,  and  is  very  largely  imported  from  Eng- 
land and  Germany. 

The  United  States  manufactures  degras  from  wool  waste  in  small 
quantities,  but  is  about  to  embark  in  its  production  on  a  larger  scale, 
and,  strange  to  say,  it  is  driven  to  do  this  because  of  the  low  price  of 
wool. 

The  opponents  of  a  tariff  on  wool  assert  that  the  great  decline  in  the 
market  price  of  wool  is  owing  not  to  tariff  legislation,  but  to  the  fact 
that  the  wool  product  of  the  world  has  doubled  since  1870,  and  is  also 
owing  to  the  large  utilization  of  cheap  substitutes  for  wool. 

An  influence  that  may  become  a  more  potent  factor  in  the  near  future, 
in  increasing  the  availability  of  the  present  supply  of  wool,  and  thereby 
diminish  the  cost,  is  the  promised  solution  of  the  vexed  problem  of  the 
saving  and  utilization  of  the  enormous  wastes  in  the  process  of  manu- 
facturing. Recently  it  has  been  boldly  asserted,  and  almost  clearly 
demonstrated  to  a  committee  of  wool  manufacturers  in  Providence,  that 
it  is  possible  to  utilize  the  by-products  that  now  go  to  waste,  so  as 
to  make  them  an  important  source  of  revenue  to  the  manufacturer.  At 
the  same  time,  by  this  new  process  of  cleaning,  called  the  solvent  pro- 
cess, the  value  of  the  fibre  would  be  enhanced  fully  one  cent  a  pound. 

It  is  asserted  that  the  amount  of  refuse  material  daily  turned  into  the 
river  by  the  wool  manufacturers  in  the  Olneyville,  R.  I.,  district  is 
6,000,000  gallons,  in  which  are  about  50,000  lbs.  of  grease  ;  and  besides 
a  large  quantity  of  logwood,  acids  and  other  substances,  far  in  excess 
of  what  is  generally  supposed.  The  consumption  of  raw  wool  in  this 
manufacturing  district  alone  is  estimated  at  20,000,000  to  25,000,000 
pounds  per  annum,  and  the  committee  stated  that  there  was  a  loss  of 
about  50  per  cent,  during  the  washing  process. 


632 


APPENDIX. 


According  to  statistics,  there  is  a  shrinkage  of  from  58  to  60  per  cent, 
on  some  500,000,000  pounds  of  wool  annually  consumed  in  the  United 
States. 

The  startling  announcement  was  made  that  the  manufacturers  were 
throwing  away  more  money  on  the  by-product  than  is  produced  by  the 
wool  product. 

The  man  who  made  this  statement  gave,  as  an  illustration,  that  they 
were  putting  into  their  streams  2,500,000  pounds  of  bicarbonate  of 
potash  and  losing  $250,000  annually.  He  also  showed  that  in  25,000,- 
000  pounds  of  wool  there  is  20  per  cent,  of  wool  fat,  and  therefore 
5,000,000  pounds  of  degras  is  thus  thrown  away.  There  are  now 
11,000,000  pounds  of  degras  imported  into  this  country  annually  from 
Europe,  and  for  every  5,000,000  pounds  of  wool  consumed,  $10,000  a 
year  is  paid  for  wool  oil  to  put  back  into  the  wool. 

The  process  proposed  by  Mr.  N.  Burton  McDowell,  of  New  York  City, 
is  effected  by  the  introduction  of  a  certain  kind  of  oil  in  the  cleansing 
pots.  This  oil  is  made  by  the  Standard  Oil  Company,  and  can  be  used 
over  and  over  again.  A  plant  is  now  being  erected  to  treat  16,000,000 
pounds  in  Lawrence,  Mass.  The  cost  of  the  process,  so  far  as  the 
cleaning  goes,  is  nil,  or  so  nearly  so  that  it  counts  for  nothing.  In  ad- 
dition, the  cloth  scourings  are  taken  and  treated  for  the  indigo  they  con- 
tain. Mr.  McDowell  has  offered  to  put  in  a  proposition,  accompanied 
by  a  bond,  to  take  the  wastes  and  treat  them  in  the  manner  proposed, 
which  the  committee  voted  would  be  satisfactory. 

This  process,  if  successfully  adopted,  may  work  a  revolution  in  the 
manufacturing  of  woolen  fabrics,  decreasing  the  cost  of  the  raw  material 
by  enhancing  its  value,  thereby  giving  a  larger  margin  of  profit  to  the 
mill  owner  while  decreasing  the  cost  of  the  manufactured  product. 

It  would  seem  from  the  above  statement  that  we  have  the  greasy 
wools  in  this  country,  from  which  to  make  a  degras  equal  to  that  which 
we  now  import  from  England  and  Germany. 

THE  PER  CENT.  OF  WATER  IN  DEGRAS. 

To  determine  the  proportion  of  water  in  degras,  says  a  correspondent 
of  La  Halle  aux  Cuirs,  there  are  two  methods  in  general  use.  The 
first  consists  of  heating  a  previously  determined  weight  of  the  degras  in 
a  clay  crucible  by  means  of  a  stove  or  a  sand  bath,  and  calculating  the 
amount  of  water  by  the  loss  in  weight.  The  temperature  in  this  opera- 
tion ought  to  be  maintained  at  2210  F.    If  it  rises  to  2390  or  2470  F., 


APPENDIX. 


633 


it  gives  out  whitish  vapors  of  a  pronounced  odor,  which  evidently  con- 
sist of  something  beside  steam.  Thus  the  chief  objection  to  this 
method — that  it  gives  results  which  are  often  too  high — is  not  without 
foundation.  If  the  operator  does  not  have  convenient  access  to  a  ther- 
mostat, or  heating  apparatus,  which  automatically  maintains  the  tem- 
perature desired,  it  requires  constant  watchfulness  and  considerable  loss 
of  time. 

The  second  method  consists  of  agitating  a  given  amount  of  degras  in 
a  graduated  tube,  with  benzine,  and  leaving  it  until  the  water  has  sep- 
arated itself,  when  the  per  cent,  may  be  calculated  by  the  graduations 
of  the  tube.  The  value  of  the  results  obtained  by  this  process  is  also 
open  to  discussion.  The  water  being  separated,  in  a  state  of  emulsion, 
it  is  impossible  to  exactly  determine  its  actual  volume.  Owing  to  the 
different  density  of  water  and  of  fatty  substance,  the  figures  obtained 
will  not  coincide  with  those  by  the  first  method,  and  they  are  also  influ- 
enced by  the  temperature  maintained.  In  view  of  the  many  possibili- 
ties of  error,  it  may  be  considered  a  happy  chance  if  the  result  approxi- 
mates the  real  amount  sought  to  determine.  In  fact,  by  either  system, 
different  analyses  of  the  same  degras  often  present  considerable  var- 
iation. 

Thanks  to  a  very  simple  artifice,  however,  it  is  an  easy  matter  to  sep- 
arate at  the  temperature  of  boiling  water  all  the  water  which  the  degras 
contains.  This  may  be  accomplished  by  pouring  upon  the  latter  from 
time  to  time  small  quantities  of  concentrated  alcohol,  which  evaporates 
the  moisture  from  the  warm  liquid.  A  platinum  capsule  should  be  used 
to  heat  a  few  grammes  of  degras  to  the  boiling  point  and  a  few  cubic 
centimeters  of  alcohol  used.  When  the  last  addition  of  alcohol  is  evap- 
orated, the  crucible  is  allowed  to  cool  and  the  contents  weighed  ;  then 
the  operation  may  be  repeated  to  make  sure  that  no  further  shrinkage 
can  be  obtained. 

This  process  does  not  require  continual  watchfulness,  it  takes  less 
time  and  excludes  any  risk  of  overheating.  The  writer  adds  that  he 
has  already  employed  it  for  some  months,  and  it  has  always  given 
constant  results.  The  idea  is  not  absolutely  new,  as  it  has  been  em- 
ployed in  pharmacy  for  separating  oleate  of  lead  from  its  moisture. 

TANNING  MATTERS. 

Our  methods  of  determination  of  tanning  matters  are  far  from  per- 
fect, and,  as  Dr.  W.  Schmitz-Dumont  truly  says  in  Der  Ledermarkt : 


634 


APPENDIX. 


The  accuracy  of  the  results  obtained  in  the  analysis  of  tanning  ma- 
terials depends  upon  the  quality  of  the  hide-powder  used.  It  is  a 
matter  of  great  difficulty  to  make  or  to  obtain  a  hide-powder  of  uni- 
formly good  quality.  In  spite  of  the  greatest  caution  observed  in 
making  the  powder,  the  best  hides  often  produce  powders  which  are 
worthless,  simply  because  they  are  not  sufficiently  insoluble  in  water  or 
because  their  structure  is  too  horny  and  gelatinous.  The  heating  of  the 
mill-stones  during  the  grinding  of  the  hide  or  the  change  in  structure 
during  the  drying  of  the  powder  will  account  for  the  uncertain  results. 
It  is  therefore  desirable  to  obtain  a  substitute  for  hide  powder,  combin- 
ing the  following  properties  : 

1.  Absorption  of  tannic  acid  in  the  same  manner  as  hide  powder. 

2.  Insolubility  in  water. 

3.  It  must  be  easily  manufactured. 

Experiments  were  first  tried  to  separate  tannin  from  solution  by 
means  of  gelatin,  hardened  with  alum  and  with  chromic  acid,  but  with- 
out success.  The  most  satisfactory  results  were  obtained  with  "  forma- 
lin-gelatins." This  is  a  commercial  article,  used  as  an  antiseptic.  It 
is  a  coarse,  sandy  powder,  and  absorbs  tannin  quantitatively  and 
quickly,  especially  when  the  solution  is  heated  to  104°  F.  But  owing 
to  the  high  price  of  the  commercial  article,  and  to  its  being  con- 
taminated with  trioxymethylene  (which  has  to  be  removed  by  long  ex- 
traction with  hot  water,  in  order  to  prevent  errors  in  the  results),  it 
seemed  desirable  to  make  this  preparation  in  the  laboratory.  The  fol- 
lowing method  was  employed  for  making  the  "formalin-gelatin  :" 

Thick,  woolly  filter  paper,  free  from  soluble  matter,  is  thoroughly  im- 
pregnated with  a  hot  10  per  cent,  solution  of  gelatin,  and  placed  hori- 
zontally on  glass  rods  to  dry  in  the  air ;  it  is  then  left  for  twenty-four 
hours  in  a  2  per  cent,  solution  of  formalin,  and  dried  at  2030  F. 
The  sheets  of  paper  now  show  a  horny  appearance,  resembling  cellu- 
loid ;  they  are  cut  into  strips  and  ground  in  a  mill  (a  coffee  mill  will 
do).    A  woolly  powder  results,  resembling  hide  powder  in  appearance. 

This  powder  is  again  treated  for  twenty-four  hours  with  a  2  per  cent, 
formalin  solution  ;  the  solution  is  then  pressed  out  and  the  powder 
dried  at  2120  F.,  until  the  loss  of  weight  is  only  0.1  per  cent,  in 
thirty  minutes'  drying.  The  preparation  must  now  be  treated  with 
hot  water  in  a  suitable  extraction  apparatus  in  order  to  remove  the  tri- 
oxymethylene ;  the  extraction  must  be  continued  until  100  cubic  cen- 
timeters of  the  extract  give  no  reaction  for  formaldehyde  with  alkaline 


APPENDIX. 


635 


resorcin  solution.  The  water  is  then  pressed  out  and  the  powder  dried 
on  the  water-bath  until  it  feels  dry.  Thirty  grams  of  the  preparation 
were  treated  with  400  cubic  centimeters  of  water  for  twenty-four 
hours,  with  occasional  shaking,  in  order  to  test  it.  300  cubic  centi- 
meters of  the  clear  filtered  liquor  on  evaporation  left  a  residue  weigh- 
ing 0.0023,  an  inconsiderable  amount  in  a  tannic  acid  determination. 

A  number  of  parallel  determinations  of  tannic  acid  were  made  to 
compare  the  action  of  the  gelatine  compound  with  hide-powder. 
Twenty  grams  pine  bark  were  extracted  with  one  liter  of  water ;  200  Cc. 
were  shaken  with  each  of  the  two  absorbents.  The  manipulation  with 
hide  powder  was  according  to  the  usual  method.  200  Cc.  of  the  extract 
solution  were  shaken  for  one  hour  with  ten  grams  of  the  gelatine  com- 
pound. The  absorption  proceeded  more  rapidly  if  the  solution  was 
warmed  to  95  or  104  F. ;  in  twenty  minutes  the  solution  was  al- 
most colorless,  and  gave  only  a  faint  reaction  with  ferric  chloride. 
The  solution  was  then  filtered  and  left  for  twenty-four  hours  with  ten 
grams  of  the  gelatine  preparation  ;  filtered  and  dried  to  constant 
weight  at  21 2°  F. 

The  following  amounts  of  non-tannins  were  obtained  per  100  Cc. 
extract : 

Gelatine 

Hide.         Gelatine.  (heated). 
Pine  I   0.1599         0.1582  0.1589 

0.1576         0.1587  0.1580 
Pine  II   0.1630  0.1605  0.1621 

    0.1613 

Oakbark  I   0.1895  0.1879  0.1888 

"    0.1870     

Oakbark  II   0.1280  0.1269  0.1280 


0.1277 


In  evaporating  the  solutions  of  non-tannins,  5  grams  of  ignited 
quartz  sand  were  added. 

The  results  obtained  were  most  favorable  for  the  "formalin-gelatin  ;" 
but  unfortunately  a  second  preparation  of  it  did  not  give  as  good  results. 
The  first  preparation  weighed  only  300  grams  ;  the  second  preparation 
amounted  to  two  kilograms.  Thirty  grams  of  the  new  preparation, 
when  treated  for  twenty-four  hours  with  400  Cc.  water,  gave  0.0063 
grams  residue  per  100  Cc.  A  further  treatment  with  water  brought  the 
weight  of  residue  to  0.0102  grams  per  10  Cc.  It  seems  probable  that 
in  manipulating  the  larger  quantity  of  material,  the  preparation  was  not 


636 


A1TENDIX. 


sufficiently  dried  to  change  the  gelatine  completely  to  the  insoluble 
form.  Or  perhaps  too  long  continued  washing  with  water  caused  the 
compound  to  revert  to  the  soluble  form.  Better  methods  of  making 
the  preparation  will  probably  be  suggested,  so  that  it  can  be  used  as  an 
infallible  substitute  for  hide  powder. 

It  is  to  be  hoped  that  the  International  Conference  of  Leather 
Trades  Chemists,  which  will  be  held  in  London  on  September  28  and 
29,  1897,  will  be  productive  of  much  good,  and  that  its  decisions  will 
regulate  the  commercial  analysis  of  tanning  materials  till  revised  by  a 
future  meeting. 

That  this  conference  has  high  aims  is  shown  by  the  following  selec- 
tion of  subjects  to  be  considered  : 

1.  Standard  method  of  drawing  samples  of  (a)  liquid  extracts;  (&) 
solid  extracts,  including  gambier;  (c)  valonia  ;  (d)  algarrobilla  and 
divi-divi ;  (<?)  general  tanning  materials. 

2.  Preparation  of  sample  for  analysis. 

3.  Preparation  of  infusion. 

4.  Method  of  determination  of  tanning  matters. 

5.  Standard  means  of  color  measurement. 

ELECTRIC  TRANSMISSION  OF  POWER. 

The  direct  application  of  power  to  machines  by  electric  motors  is  a 
subject  which  has  latterly  claimed  a  good  deal  of  the  attention  of 
tanners,  and  a  number  of  them  have  introduced  the  "direct  drive"  in 
their  establishments  with  very  satisfactory  results.  The  designers  and 
builders  of  the  electric  motors  are  the  Northern  Electrical  Mfg.  Co., 
Madison,  Wis.,  and  the  claims  they  make  for  their  appliances  are 
obvious  and  well  worth  the  examination  of  all  users  of  machinery. 
They  calculate  that  the  motors  save  thirty  per  cent,  of  floor  space, 
compared  with  line  shaft  transmission.  A  number  of  machines  with 
line  shafting  use  up  nearly  double  the  floor  space  they  would  otherwise 
occupy,  and  then  they  frequently  are  placed  at  great  disadvantage  with 
reference  to  the  handling  of  raw  material  and  the  manufactured  pro- 
duct, and  in  relation  to  other  machines  performing  kindred  work. 
With  the  "direct  drive"  each  machine  may  be  located  absolutely  at 
the  will  of  the  manufacturer.  Besides  the  better  arrangement  of  the 
mechanism,  there  is  a  large  saving  in  hangers,  shafts,  belts,  pulleys,  etc., 
and  also  in  power.  It  is  estimated  that  in  the  average  establishment 
there  is  a  loss  on  power  delivered  from  the  engine  of  forty  per  cent. 


APPENDIX. 


637 


The  company  claim  that  with  their  direct  connection  these  losses 
should  not  exceed  twenty  per  cent,  of  the  total  power  delivered. 
When  any  machine  is  stopped,  the  consumption  of  power  is  stopped 
likewise. 

Direct  electric  motor  drive  is  also  claimed  to  yield  a  further  material 
gain  arising  from  the  increase  in  the  daily  output  of  each  driven  ma- 
chine, and  consequently  a  very  material  gain  in  the  output  per  man 
throughout  the  entire  force  employed,  thus  greatly  increasing  the 
amount  of  manufactured  product  per  dollar  of  wages  paid.  There  is 
also  an  absolute  control  of  speed.  It  may  be  made  uniform  or  varied 
at  will,  thus  enabling  each  machine  to  be  operated  at  its  most  profitable 
speed. 

The  tan  drums  of  the  Pfister  &  Vogel  Leather  Co.,  Milwaukee,  are 
driven  with  these  motors,  and  the  company  say  they  are  giving  perfect 
satisfaction.  E.  C.  Fisher  &  Co.,  Gowanda,  N.  Y.,  have  equipped  their 
tannery  complete  with  electrical  generators  and  special  tannery  motors 
and  fixtures,  and  say  : 

"To  say  that  we  are  pleased  with  the  work  you  have  done  and  the 
operation  of  your  machinery,  would  scarce  do  the  subject  justice.  We 
already  note  the  manifest  saving  in  power  and  labor  through  direct  ap- 
plication of  the  power  and  the  great  convenience  of  placing  the  ma- 
chinery. We  are  much  pleased  with  the  strength,  compactness  and 
ease  of  operation  of  the  equipments,  all  of  which  go  from  the  first  start 
without  any  trouble  or  hindrance.  You  have  solved  the  economy 
question  for  the  tanners  of  the  world,  and  we  heartily  recommend  your 
equipments  to  the  trade." 

The  Northern  Electrical  Manufacturing  Co.  have  issued  a  useful 
pamphlet  (catalogue  No.  7)  showing  their  devices  as  used  in  connec- 
tion with  tanning  machines  of  various  descriptions,  and  it  is  replete 
with  valuable  information  on  the  subject. 

TO  DRESS  STRAP,  POCKET-BOOK,  BAG,  CASE  AND  WELT  LEATHER  AN  I ) 
FLEXIBLE  SPLITS. 

Soak  the  stock  so  as  to  wet  it  through  and  skive  off  the  rough  flesh. 
Then  jack  the  sides  well  on  the  grain  in  order  to  impart  as  much 
smoothness  as  possible.  Then  split  them  for  any  substance  required. 
After  they  are  split  shave  them  ;  afterward  mill  them  ;  for  every  twenty- 
five  sides  give  them  five  to  six  pounds  of  borax  for  thirty  minutes ; 
wash  off  clean  ;  then  add  sumac  with  two  pails  of  well  scalded  sumac 


638 


APPENDIX. 


with  water  enough  to  make  the  mixture  twenty  gallons  ;  add  one  pint 
of  sulphuric  acid  to  the  sumac  liquor  and  mill  for  two  hours ;  wash  off ; 
give  them  one  pound  of  oxalic  acid  dissolved  in  a  pail  of  water ;  mill 
ten  minutes  more  and  wash  off ;  take  the  sides  out  and  slick  them  off, 
they  are  then  ready  for  coloring.  If  coloring  is  not  desired  they  will 
make  nice  russet  leather  by  giving  them  one  pound  of  muriate  of  tin 
before  slicking  them  out  ;  if  the  stock  is  for  strap,  half  dry  them  and 
moss  them  well  on  the  flesh,  set  them  out  well  on  the  grain  and  tack 
them  on  frames  ;  stretch  them  well  when  they  are  dry,  strip  them  from 
the  frames,  trim  and  moss  them  on  the  flesh  and  jack,  hang  up  and 
dry,  then  dampen  them  with  a  weak  oxalic  acid  on  the  grain  and  glass 
them  out  smoothly  ;  then  give  them  a  good  seasoning  of  flaxseed  ;  hang 
up  and  dry  ;  when  they  are  dry,  roll  them  ;  then  brush  or  felt  on  the 
grain  and  they  are  finished.  If  bag  or  pocketbook  stock  is  wanted  the 
sides  should  not  be  mossed,  because  mossing  stiffens  them  and  bag 
leather  should  be  seasoned  with  egg  albumen  and  milk  or  starch  and 
milk,  one-half  pound  starch  and  one  pint  of  milk.  If  two  ounces  of 
gum  arabic  are  mixed  with  every  pail  of  seasoning,  a  better  finish  will 
be  imparted.  If  black  stock  is  wanted  use  blood  albumen,  five  ounces 
to  the  pail,  more  or  less,  according  to  the  stock.  If  it  is  coarse,  use 
more  blood  with  a  little  milk  ;  when  the  stock  is  seasoned  and  dry, 
glaze  it ;  then  dampen  it  well  on  the  grain,  pack  the  sides  down,  cover 
them  up,  put  a  weight  on  them  and  let  them  lie  from  five  to  ten  hours ; 
then  pebble  them,  and  while  they  are  damp  grain  them,  hang  up  and 
dry ;  when  dry,  glaze,  grain  and  felt  or  brush  and  they  are  finished. 
The  splits  that  come  off  these  sides,  if  heavy  enough,  can  be  put  into 
flexibles.  Mill  and  sumac  them  as  you  would  sides,  but  give  them  no 
muriatic  acid,  and  when  they  are  milled  slick  them  on  the  flesh  side  ; 
when  they  are  slicked  out  moss  them  on  flesh,  turn  them  over  and 
slick  them  out  well  on  the  grain,  and  moss  and  tack  them  on  the 
frames  ;  when  they  are  dry,  trim,  moss  and  jack  both  sides;  then  dry 
and  they  are  finished.  For  welt  leather  skive  the  stock  clean  and  jack 
the  sides  well,  and  then  level  them  off  with  the  machine  ;  give  them  a 
good  scouring  on  both  sides  out  of  warm  water  ;  afterward  a  good 
sumac  liquor  for  twenty-four  hours  at  1400  F. ;  slick  them  out  half  dry, 
then  set  out  on  the  grain  ;  give  them  a  weak  oxalic  acid  and  a  water 
stuffing  on  the  grain,  turn  them  over,  strike  them  out  tight  on  the  flesh 
and  give  them  a  light  stuffing ;  hang  up  when  they  are  half  dry,  reset 
them  and  dry  them  out ;  then  glass  and  brush  them  on  both  sides,  when 
they  are  finished. 


APPENDIX. 


639 


LIST  OF  PATENTS  RELATING  TO  THE  MANUFACTURE 
OF  LEATHER,  ISSUED  BY  THE  GOVERNMENT  OF 
THE  UNITED  STATES  OF  AMERICA,  FROM 
JANUARY  1,  1884,  TO  AUGUST  31,  1897* 


PROCESSES  AND  COMPOSITIONS. 

Extracts. 


Patents  for  extracting  tan  are  classed  with  those  for  extracting  dye 
woods  or  drugs,  the  processes  being  substantially  similar,  as  well  as 
much  of  the  apparatus.    The  patents  here  cited  refer  only  to  tan  bark. 


No. 

Date. 

Inventor. 

Residence. 

302,105 

July  '5- 

1884. 

Eniile  L.  P.  and  Gus- 

St.  Denis,  France. 

tave  C.  Coez, 

393.976 

Dec.  4, 

1888. 

M.  Gross, 

New  York  City. 

394.J9I 

Dec.  11, 

1888. 

J.  H.  Lorimer, 

Philadelphia,  Pa. 

444,068 

Jan.  6, 

1891. 

J.  and  W.  N.  Hutchings, 

Warrington,  England. 

466,152 

Dec.  29, 

1891. 

H.  S.  Blackmore, 

Mt.  Vernon,  N.  V. 

503.237 

Aug.  15, 

1893- 

M.  Heftier  and  G.  Ber- 

Paris, France. 

nard, 

505,816 

Oct.  3, 

1893- 

S.  W.  Cochran, 

Lambertville,  N.  J. 

510,132 

Dec.  5, 

1893- 

Otto  C.  Hagemann, 

New  York  City. 

541,410 

June  18, 

1895. 

\V.  Albach, 

Hochst,  Germany. 

571.635 

Nov.  17, 

1896. 

John  S.  Adriance, 

New  York  City. 

Depilating. 

No. 

Date. 

Inventor. 

291,953 

Jan.  15,  1884. 

A.  H.  Stone, 

306,640 

Oct.  14,  1884. 

P.  H.  P.  Goulet, 

359.136 

June    2,  1885. 

E.  Schroeder, 

322,521 

July  21,  1885. 

T.  R.  Clark, 

330.7I5 

Nov.  17,  1885. 

S.  R.  Kennedy, 

330,790 

Nov.  17,  1885. 

S.  R.  Kennedy, 

434-645 

Aug.  19,  1890. 

J.  Schmitt, 

450,032 

April  7,  1 89 1. 

J.  Perl, 

481,5 16 

Aug.  23,  1892. 

R.  L.  Tudor, 

490,791 

Jan.  31,  1893. 

J.  Mellinger, 

499,134 

June   6,  1893. 

J.  Mellinger, 

5!9,345 

May    8,  1894. 

C.  L.  Puech, 

520,005 

May  15,  1894. 

J.  Mellinger, 

545,56o 

Sept.  y  1895. 

G.  C.  Walter, 

555,050 

Feb.  18,  1896. 

Pierson  and  Moor 

Residence. 
New  York  City. 
Reims,  France. 
San  Francisco,  Cal. 
New  York  City. 
Philadelphia,  Pa. 
Philadelphia,  Pa. 
Allegheny,  Pa. 
Berlin,  Germany. 
Cincinnati,  O. 
Waverly,  Md. 
Baltimore,  Md. 
Mazamet,  France. 
Baltimore,  Md. 
Hastings,  Mich. 
Philadelphia,  Pa. 


*The  first  edition  of  this  book,  published  November  22,  1884,  contains  the  Lists 
of  Patents  issued  by  the  Government  from  1790  to  1883,  inclusive. 


640 


No. 

Date. 

461,010 

Oct.  13, 

1 09 1 . 

359.36o 

Mar.  15, 

1887. 

4H.034 

Sept.  17, 

1889. 

4I3.6I5 

Oct.  22, 

1889. 

444.77" 

Jan.  13, 

1891. 

450,930 

April  2 1 , 

1891. 

450.954 

April  21, 

1891. 

452.27i 

May  12, 

1891. 

45  5.85 1 

July  14, 

1891. 

549.193 

Nov.  5, 

1895- 

580,21 1 

April  6, 

1897. 

No. 

Date 

Feb.  12. 

[884. 

30O.3S2 

lune  17, 

1884. 

302,132 

July  15, 

884. 

TO4,Q';8 

Sept.  9, 

[884. 

3OQ.70I 

Feb.  23, 

884. 

320,603 

Tune  23, 

[885. 

'526.7:;'? 
-J      '  IJJ 

Sept.  22, 

1885. 

338,182 

Mar.  16, 

1886. 

3S0.706 

Oct.  1  2, 

886. 

1ZI  .20A 

Oct.  19, 

[886. 

JJJ'JT  1 

Nov.  30. 

886. 

Dec.  27, 

887. 

375.845 

Jan.  3, 

[888. 

387.957 

Aug.  7, 

(888. 

396,337 

Jan.  15. 

889. 

4H.931 

Oct.  1, 

889. 

411,932 

tt 

435.922 

Sept.  9, 

[890. 

447.427 

Mar.  3, 

891. 

448,420 

Mar.  17, 

[891. 

450,121 

April  7, 

891. 

450,998 

April  21, 

.891. 

453.295 

June  2, 

[891. 

459,993 

Sept.  22, 

.891. 

461,108 

Oct.  13, 

891. 

464,423 

Dec.  1, 

.891. 

473.805 

April  26, 

[892. 

504,013 

Aug.  29, 

■893- 

517.083 

Mar.  27, 

[894. 

526,229 

Sept.  18, 

1894- 

528,427 

Oct.  30, 

[894. 

536,019 

Mar.  19, 

.895. 

539,488 

May  21, 

>895- 

542,680 

June  16,  ] 

895. 

555,028 

Feb.  1 8, 

[896. 

562,781 

June  23, 

[896. 

564,086 

July  14, 

[896. 

APPENDIX. 
Bating. 

Inventor. 

C.  W.  Cooper, 
E.  P.  Nesbit, 
A.  Hull, 
W.  Dieterle, 
M.  Wilson, 
W.  Dieterle, 
W.  Oetlinger, 
Hull  and  Burns, 
H.  Poydenot, 
O.  Geisler, 
W.  Dieterle, 

Tanning. 

Inventor. 
L.  Schnadel, 
S.  S.  Eddy, 
E.  W.  Hewitt, 
J.  Roberts, 
S.  S.  Eddy, 
E.  S.  Ward, 

G.  H.  Leonard, 
A.  Muller, 
Mary  Sutherland, 
J.  T.  Khyne, 

H.  L.  Wilcox, 
Millochau  and  Chailly, 
W'aer,   Phillips  and 

Kengla, 
C.  H.  Perrin, 
J.  Lalor, 

G.  H.  Russell, 

T.  L.  Crafton, 
W.  E.  Hedges, 
J.  Engelke, 
C.  B.  Warrand. 
W.  Dieterle, 
J.T.  Smith, 

H.  Churchill, 
R.  W.  Turner, 
Bro\vn,Clark  and  Brown, 
S.  W.  Wright, 

W.  Zahn, 

C.  B.  Warrand, 
J.  B.  Hodges, 

D.  A.  Goodman, 
S.  and  G.  Durio, 
W.  A.  Ragland, 
H.  A.  Leverett, 
J.  H.  Thompson, 
J.  Durio, 

C.  Knees, 


Residence. 
Brooklyn,  N.  Y. 
Surrey,  England. 
West  Winsted,  Conn. 
Feuerbach,  Germany. 
Becket,  Mass. 
Feuerbach,  Germany. 
Philadelphia,  Pa. 
Boston,  Mass. 
Bayonne,  France. 
Gloversville,  N.  Y. 
Feuerbach,  Germany. 


Residence. 
Chicago,  111. 
Rochester,  N.  Y. 
Louisville,  Ky. 
Portville,  N.  Y. 
Rochester,  N.  Y. 
Newark,  N.J. 
Landisburg,  Pa. 
New  York  City. 
Diamond,  Mo. 
Durant,  Mo. 
Lincoln,  Neb. 
Paris,  France. 
Tucson,  Arizona. 

Jefferson  City,  Mo. 
Independence,  la. 
Newburg,  Pa. 

Sidney)  Ark. 
Polk  Bayou,  Ark. 
Cincinnati,  O. 
Savannah,  Ga. 
Feuerbach,  Ger. 
San  Francisco,  Cal. 
Rochester,  N.  Y. 
Dublin,  Texas. 
South  Fork,  Mo. 
Mountain  Grove,  Mo. 
Newark,  N.  J. 
Savannah,  Ga. 
Salem,  Ark. 
Salisbury,  N.  C. 
Turin,  Italy.  | 
Springfield,  Mo. 
London,  England. 
Columbus,  Ind. 
Turin,  Italy. 
Oshawa,  Canada. 


APPENDIX. 


641 


Tawing* 


No. 

Date. 

I  nventor 

Residence. 

291,784 

t„„         ft.  iftft^ 

|an.     0,  1  vvj. 

A,  r>cnuitz, 

New  York  City. 

291,785 

T__                 ft         I  ft«  A 

Jan.     0,  I004- 

A.  bcnultz, 

JNew  York  City. 

323>973 

Uct.  27,  Ioo5- 

G.  f4.  Schweitzer, 

Lincoln,  Neb. 

33  !>942 

n*>r       ft  iftSr 

1 .  i\.  *_,iark, 

New  \  ork  City. 

340,199 

A  r\ril  on    t  SftA 
.April  20,  I00D. 

S.  J.  Dobson, 

Lincoln,  Neb. 

343,166 

T*mwm.At         ft        -  OQA 

|une    0,  iSoo. 

J.  W.  rnes, 

Salem,  N.  C. 

343>I07 

|UllL      O,    I  OOO. 

j .  v v .  r  nes, 

r>aiem,  in  . 

345'8a7 

T,,1,,    on    r  ftftA 

T     C  Pilnrlll^v 

j .  0.  xjiiw nier, 

St.  Gall,  Switzerland. 

349>589 

"Sept.  21,  1886. 

( 1 .  \\  .  Hersey, 

Rmpire,  Wis. 

3D7>>45 

July    2D,  looy. 

C  Kuestner, 

Magdeburg,  Prussia. 

38l'73° 

A  t-n-il  0  a     T  ftftft 
.April  24,  looo. 

J.  Townsend, 

Glasgow,  Scotland. 

381,734 

.April  looo. 

VVarter  and  Koegel, 

Newark,  N.  J. 

383.379 

May  22,  looo. 

Snow  and  Howard, 

Wichita,  Kansas. 

385,222 

ryf.        .  ftftft 

June  20,  1000. 

w .  Aann, 

Newark,  N.  J. 

389,150 

oept.  4*  1  ooO' 

j .  11  oeick, 

Chicago,  111. 

4OI>434 

A  r^»-il  r  i\    1  ftftn 

/April  10,  1009. 

J.  W.  IllLL, 

Lisie,  IN  .  1  . 

401,715 

A  T-n-tl  1  A    1  ftftr* 

April  1 0,  I  ooy- 

t.rik  \  'iscad  wnesiau, 

ot.  1  aui,  M  inn. 

409,336 

Aug.  10,  1889. 

L.  Kappe, 

^n  ewarii,  i> .  1 . 

A  A  1   A  Si  A 
442,0O4 

eb,  16,  1890. 

A.  P.  Krueger, 

ivanKaKee,  111. 

4SI>385 

April  28,  1 89 1  ■ 

j .    ri.     ivic  w  mrter. 

Moody,  Mo. 

Langley  and  Upton, 

455.674 

July    7»  io9*- 

\j.  K^.  W  alter, 

Hastings,  Mich. 

450,855 

Tulir    oft     t  ftr»  1 

j  uiy  20,  1 09  *  ■ 

C.  L.  Royer, 

Halifax,  England. 

472,701 

April  1 2,  1 892. 

H.  Endemann, 

isrooKivn,  in.  \  . 

495,028 

April  1 1,  1893. 

M.  Dennis, 

orooklyn,  IN.  Y. 

498,067 

May  23,  1893. 

A.  D.  Little, 

Boston,  Mass. 

498,077 

May  23,  1893. 

W.  M.  Norns, 

Fnnceton,  N.J. 

498,214 

May  23,  1893. 

W.  M.  Norris, 

Princeton,  N.  J. 

501,586 

July  18,  1893. 

1 .  VV.  Clayton, 

Barren  Fork,  Ark. 

504,01 2 

Aug.  29,  1893. 

v\ .  Aann, 

iNewarK,  in.  j. 

504,014 

Aug.  29,  1893. 

w .  /.ann, 

INcWdrK,  IN.  J. 

506,696 

Oct.  17,  1893. 

J.  H.  James, 

l>dbll\  lllc,  niK, 

5 1 1 ,007 

Dec.  19,  1893* 

w  .  /.aim, 

in  e vv  ai  k  ,  in  .  1 . 

51  r>301 

Dec.  19,  1893* 

W.  I* .  Lawley, 

Kennedy,  Ala. 

511,411 

Dec.  20,  1093. 

M .  I  )ennis, 

Newark,  N.  J. 

518,467 

April  1 7,  1 894. 

W.  M.  Norris, 

Princeton ,  N .  | . 

528,162 

Oct.  30,  1894. 

C.  Heinzerling, 

Frankfort*  0  n  •  M  a  i  n 
Germany. 

542,971 

T  1 

July  16,  i895' 

O.  P.  Amend, 

.ncw   1  ori\  v_  ny . 

Mar.  10,  1896. 

S.  P.  Sadtler, 

Philadelphia,  Pa. 

561,044 

May  26,  1896. 

S.  Chadwick, 

Philadelphia,  Pa. 

563.559 

July    7,  1896. 

T.  E.  Burlingame, 

Central  Falls,  R.  I. 

563,560 

563.56l 

564,106 

July  14,  1896. 

J.  C.  Rogers, 

Cuero,  Texas. 

573.362 

Dec.  15,  1896. 

H.  Schweitzer, 

Englewood,  N.  J. 

573.631 

Dec.  22,  1896. 

G.  W.  Adler, 

Philadelphia,  Pa. 

574,014 

Dec.  29,  1896. 

Wagner  and  Maier, 

Philadelphia,  Pa. 

5  79,000 

Mar.  16,  1897. 

C.  Marter, 

London,  England. 

582,960 

May  18,  1897. 

J.  A.  Schweitzer, 

Stains,  France. 

588,874 

Aug.  24,  1897. 

W.  M.  Norris, 

Princeton,  N.  J. 

*  The  conversion  of  hides  and  skins  into  leather  by  the  aid  of  mineral  substances. 


41 


642 


APPENDIX. 


Curry  ing. 

Inventor. 

J.  A.  J.  Schultz, 
J.  J.  Hayward, 

A.  Sommer, 
W.  B.  Davis, 

G.  C.  Seeberger, 
F.  Riegert, 
J.  Sanzenbacher, 
T.  E.  M.  Bourgeois, 

B.  P.  Bradford, 

Preserving. 

Inventor. 
F.  Latulip, 

F.  Latulip, 

Grether  and  Mosher, 

F.  Groguet, 

G.  Ruemelin, 
E.  Menowsky, 


Coloring  and  Polishing. 


No. 

Date. 

Inventor. 

295»653 

Mar.  25, 

1884. 

L.  Klopfer, 

325.32o 

Sep.  1, 

1885. 

G.  S.  Colburn, 

329,960 

Nov.  10, 

1885. 

A.  Schmitt, 

346,581 

Aug.  3, 

1886. 

E.  Z.  Coffee, 

363.420 

May  24, 

1887. 

J.  Prickett, 

365.854 

M'  5. 

1887. 

H.  C.  Parker, 

378,325 

Feb.  21, 

1888. 

C.  L.  Leonard, 

381,680 

April  24, 

1888. 

L.  C.  Dewillers, 

383,5 11 

May  29, 

1888. 

A.  S.  Ashcroft, 

397.803 

Feb.  12, 

1889. 

S.  C.  Howell, 

401,390 

April  16, 

1889. 

C.  D.  St.  Pierre, 

402,731 

May  7, 

1889. 

E.  Frid, 

405,763 

June  25, 

1889. 

G.  H.  Bishop, 

406,102 

July  2, 

1889. 

G.  Langenhagen, 

406,901 

July  16, 

18S9. 

W.  E  Harter, 

418,414 

Dec.  31, 

1889. 

G.  T.  Landauer, 

425,919 

April  15, 

1890. 

Wallace  and  Wallace 

432,853 

July  22, 

1890. 

Baulch,   Steele  and 

Evans, 

438,470 

Oct.  14, 

1890. 

W.  W.  Crooker, 

439,607 

Jan.  28, 

1890. 

O.  II.  Shaw, 

441,010 

Nov.  18, 

1890. 

J.  M.  Jolly, 

449,339 

Mar.  31, 

1891. 

G.  P.  Tipton, 

45^427 

April  28, 

1891. 

J.  \V.  Foster, 

Reissue  "1 

Feb.  10, 

1891. 

W.  W.  Crooker, 

11,144/ 
458,828 

Sep.  1, 

1891. 

G.  H.  Farthing, 

466,429 

Jan.  5, 

1892. 

W.  F.  Sampson, 

469,385 

Feb.  23, 

1892. 

W.  W.  Crooker, 

473,679 

April  26, 

1892. 

J.  F.  Thompson, 

474,702 

May  10, 

1892. 

J.  E.  Swain, 

No. 

Date. 

337.289 

Mar.   2,  1886. 

399,893 

Mar.  9,  1889. 

408,360 

Aug.  6,  1889. 

449.437 

Mar.  31.  1891. 

458^32 

Aug.  18,  1891. 

467,200 

Jan.  19,  1892. 

482,199 

Sep.    6,  1892. 

526,769 

Oct.    2,  1894. 

547.985 

Oct.  15,  1895. 

No. 

Date. 

341,583  May  11,  1886. 

Reissue  j  Dec.  21,  1886. 

10,792/ 

361,999  April  26,  1887. 

503,235  Aug.  15,  1893. 

503,987  Aug.  29,  1893. 

552,497  Dec.  31,  1895. 


Residence. 
St.  Louis,  Mo. 
Ballston,  N.  V. 
Berkeley,  Cal. 
Newport,  N.  Y. 
Munchberg,  Germany. 
St.  Joseph,  Mo. 
Canlield,  O. 
Paris,  France. 
Worcester,  Mass. 


Residence. 
Syracuse,  N.  Y. 

Syracuse,  N.  Y. 

South  Bend,  Ind. 
Bourbevoie,  France. 
Milwaukee,  Wis. 
New  York  City. 


Residence. 
Munich,  Germany. 
Gardner,  Mass. 
New  Orleans,  La. 
Philadelphia,  Pa. 
Pittsfield,  Mass. 
Wilmington,  Del. 
Grafton,  Mass. 
Brooklyn,  N.  Y. 
Brandenburg,  Ky. 
Newark,  N.  J. 
Brooklyn,  N.  Y. 
New  Hamburg,  N.  Y. 
Revere,  Mass. 
Leipzig,  Germany. 
West  Nanticoke,  Pa. 
Frankfort  on  Main.Ger. 
Clay  Center,  Neb. 
St.  Louis,  Mo. 

Lynn,  Mass. 
Toms  Brook,  Va. 
Martin,  Texas. 
Hot  Springs,  Ark. 
Detroit,  Mich. 

Lynn,  Mass. 

San  Jose.  Cal. 
Saugus,  Mass. 
Lynn,  Mass. 
Rockland,  Mass. 
Baltimore,  Md. 


APPENDIX. 


643 


No 

Date. 

492,836 

Mar. 

7- 

1893- 

494.5 '4 

Mar.  28,  1893. 

501,311 

July 

II. 

1893- 

5OI>312 

July 

I 1. 

1893- 

5°4.j39 
536,966 

Sep. 

5. 

1893- 

April 

2, 

■895- 

539.323 

May 

>4. 

1895- 

542,100 

July 

2, 

1895. 

545.505 

Sep. 

3. 

1895. 

545.734 

Sep. 

3. 

•895- 

546,876 

Sep.  24, 

1895. 

555.537 

Mar. 

3. 

1896. 

572.439 

Dec. 

1, 

1896. 

576,918 

Feb. 

9, 

1897. 

583.871 

June 

1897. 

588,000 

Aug. 

10, 

1897. 

588,471 

Aug. 

•7, 

1897. 

Inventor. 
J.  Riegert, 
J.  F.  Thompson, 
Albertson  and  Briggs, 
Albertson  and  Briggs, 
Z.  T.  Fowler, 
R.  Owens, 
Woods  and  Maclay, 
R.  Ergang, 
F.  A.  Hurd, 
J.  Scholl, 
J.  B.  Bernard, 
Stevens  and  Schroeder, 
Jane  Moore, 
A.  L.  Thompson, 
Travis  and  Karly, 
Wm.  M.  Norris, 
H.  A.  Quigley, 


Residence. 

St.  Joseph,  Mo. 
Rockland,  Mass. 
Rockland,  Mass. 
Rockland,  Mass. 
Santa  Rosa,  Cal. 
Orleans,  Cal. 
Wurtsborough,  N.  Y. 
Magdeburg,  Germany. 
Red  Bank,  N.  J. 
Brooklyn,  N.  V. 
St.  Paul,  Minn. 
Arago,  Oregon. 
Cambridge,  Mass. 
Rock  Creek,  O. 
Peabody,  Mass. 
Princeton,  N.  J. 
Milford,  N.  H. 


APPARATUS. 


Coloring  and  Polishing. 


No. 

Date. 

Inventor. 

Residence. 

320,906 

June  30,  1885. 

F.  B.  Batchelder, 

Maiden,  Mass. 

322,606 

July  21,  1885. 

J.  Hodskinson, 

Salem,  Mass. 

385.933 

July  10,  1888. 

I.  G.  Hooper, 

Newark,  N.  J. 

427.697 

May  13,  1890. 

J.  Kristen, 

Brunn,  Moravia. 

436,363 

Sep.  16,  1890. 

A.  Travis, 

Gloversville,  N.  Y. 

442,628 

Dec.  23,  1890. 

T.  J.  Faulkner, 

Lynn,  Mass. 

456,605 

July  28,  1891. 

A.  Travis, 

Gloversville,  N.  Y. 

477,761 

June  28,  1892. 

C.  Knabe, 

Osterwieck,  Germany 

498,120 

May  23,  1893. 

A.  F.  Jones, 

C.  H.*and  A.  A.  Lappe, 

Salem,  Mass. 

504,224 

Aug.  29,  1893. 

Allegheny,  Pa. 

5 1 3.642 

Jan.  30,  1894. 

A.  F.  Jones, 

Salem,  Mass. 

542,439 

July    9,  1895. 

Enos  and  Pratt, 

Peabody,  Mass. 

578,060 

Mar.   2,  1897. 

C.  E.  House, 

Yates,  Mich. 

579.I4I 

Mar.  23,  1897. 

R.  N.  Dunn, 

Philadelphia,  Pa. 

Leather  Measuring. 


No. 

Date. 

Inventor. 

Residence. 

329.596 

Nov.  3,  1885. 

VV.  A.  Sawyer, 

Danversport,  Mass. 

329,597 

Nov.  3,  1885. 

514,821 

Feb.  13,  1894. 

J.  E.  Fortin, 

Quebec,  Canada. 

Rossing  Bark. 

No. 

Date. 

Inventor. 

Residence. 

300,829 

June  24,  1884. 

F.  F.  Angermaier, 

Ravensburg,  Wurtem- 

berg,  Germany. 

300,996 

June  24,  1884. 

F.  Merziger, 

Trier,  Prussia. 

305.322 

June  24,  1884. 

314,876 

Mar.  31,  1885. 

T.  Poole  and  F.  P. 

Orange,  Mass. 

Snow, 

368,968 

Aug.  30,  1887. 

F.  M.  Purinton, 

Providence,  R.  I. 

379.559 

Mar.  20,  1888. 

N.  H.  Brokaw, 

Kaukauna,  Wis. 

397.'  14 

Feb.    5,  1889. 

N.  H.  Dolsen, 

St.  Ignace,  Mich. 

416,784 

Dec.  10,  1889. 

T.  F.  Horn, 

Livermore  Falls,  Me. 

644  APPENDIX. 


No. 

Date. 

Inventor. 

Residence 

43I»I54 

Juiy  l> 

1 090. 

r .  11 .  and  A.  fc..  Stearns, 

rLden,  V  t. 

4»9>*  7" 

Jan.  3, 

1893. 

K.I.  D10SS, 

i  aimer,  in  .  i . 

489,251 

Jan.  3, 

I8O3. 

w.  1  laaiey  ana  a.  l . 

Shelton,  Conn. 

ivici^onaia, 

CIO  7Q  C 

Dec.  12, 

I893. 

W.  W.  D.  Jeffers, 

Ficonderoga,  N.  Y. 

515.537 

Feb.  12, 

1894. 

A.  E.  Stearns, 

Eden,  Vt. 

5 1 6,09 1 

Mar.  6, 

1894. 

E.  C.  Hargreave, 

Bay  City,  Mich. 

517,990 

April  10, 

1894. 

W.  W.  and  F.N. Trevor, 

Lockport,  N.  Y. 

528,664 

Nov.  6, 

1894. 

C.  E.  V.  Folin, 

Hammerby,  Sweden. 

528,873 

Nov.  6, 

1894. 

W.  Hadley, 

Shelton,  Conn. 

540,980 

June  11, 

1895. 

E.  C.  Hargreave, 

Bay  City,  Mich. 

572,948 

Dec.  15, 

I896. 

A.  E.  Beals, 

Norwich,  N.  V.r 

579.946 

Mar.  30, 

1887. 

P.  Etches, 

Tupper  Lake,  N.  V. 

Grinding  Mills  for  Bark. 


No. 

Date. 

I  n  ventor. 

300,048 

June  io, 

1884. 

T     H  C\  1  r-1  - 

Springfield,  Mass. 

305. 7" 

Sep.  23, 

1884. 

t  T   1  >i,;it;. 
J .  \ .  rnillips, 

Grand  Rapids,  Mich. 

32I>725 

Jul)'  7, 

1885. 

0.  noiDrooK, 

Kenosha,  Wis. 

325'849 

Sep.  8, 

1885. 

J.  McKenclrick, 

■  JNew  York  L-ity. 

329,113 

Oct.  27, 

1885. 

W.  A.  Woods, 

Santa  Cruz,  Cal. 

332,796 

Dec.  22, 

1885. 

J.  C.  Hagerty, 

332,797 

Dec.  22, 

1885. 

it       n  a 

332,854 

Dec.  22, 

1885. 

W.  A.  Woods, 

Santa  Cruz,  Cal. 

334,859 

Jan.  26,  1886. 

J.  C.  Hagerty, 

335,532 

Feb.  2, 

1886. 

-La  Crosse,  Wis. 

335-533 

Feb.  2, 

1886. 

it 

tt       tt  a 

340,922 

April  27, 

1886. 

35 1>1 78 

Oct.  17, 

1886. 

X3.  noiDrooK, 

Milwaukee,  Wis. 

355, '79 

Dec.  28, 

1886. 

K.  rvirDy, 

Santa  Cruz,  Cal. 

Til  )j  V a  /f 

J.  tt  it     r  It I J  . 

No. 

Date. 

Inventor. 

Residence. 

308,803 

Dec.  II, 

1884. 

R.  Spitta, 

Brandenburg-o 

Havel,  Prussia. 

321,300 

June  30, 

1885. 

T.  Johnstonbaugh, 

Clearfield,  Pa. 

324,916 

Aug.  25, 

1885. 

Bull  and  Hill, 

Limestone,  N.  V. 

328,984 

Oct.  27, 

1885. 

T.  R.  Tuttle, 

Salem,  Mass. 

332,45' 

Dec.  15, 

1885. 

L.  Simpson, 

Bellevue,  Pa. 

380,890 

April  10, 

1888. 

J.  Head, 

York,  Pa. 

386,488 

July  24, 

1888. 

A.  A.  Myers, 

Lancaster,  Pa. 

483,734 

Oct.  4, 

1892. 

B.  P.  Bradford, 

Worcester,  Mass. 

510,500 

Dec.  12, 

1893- 

T.  Clarke, 

Stockport,  England. 

5H,549 

Feb.  13, 

1894. 

W.  T.  Harrison, 

Pooler,  Ga. 

571,678 

Nov.  17, 

1896. 

A.  A.  Myers, 

Lancaster,  Pa. 

Endless  Belts. 

No. 

Date. 

Inventor. 

Residence. 

33I>o85 

Nov.  24, 

1885. 

A.  W.  Reid, 

Ballston  Spa,  N.  V. 

356,101 

Jan.  18, 

1887. 

E.  A.  Curry, 

Winchester,  Mass. 

389,511 

Sept. '11, 

1888. 

W.  M.  Hoffman, 

Detroit,  Mich. 

479,072 

July  19, 

1892. 

A.  A.  Hunting, 

Salem,  Mass. 

497,003 

May  9, 

•893- 

Dawson   and  Schu- 

Boston, Mass. 

macher, 

584,123 

June  8, 

1897. 

W.  B.  Turner, 

Somerville,  Mass. 

APPENDIX. 


645 


Splitting? 

No. 

Date. 

Inventor. 

291,641 

Jan. 

.OO  . 
I  OO4. 

T.  S.  Strong, 

295,629 

Mar.  25, 

I  OO4. 

H.  S.  Ginther, 

295-787 

Mar.  25, 

.OO. 
I  OO4. 

B.  McKeen, 

305,240 

Sept.  16, 

»  CO  . 

1 004. 

J.  A.  Safford, 

306,760 

Oct.  24, 

«  GC  A 

1 554. 

J.  T.  Krebs, 

3I9.357 

June  2, 

1885. 

G.  L.  Tyler, 

332,385 

Dec.  15, 

,00. 

1055. 

E.  Cummings, 

337.820 

Mar.  16, 

loot). 

A.  E.  Dodge, 

339.990 

April  13, 

¥  CCA 

J.  A.  Josselyn, 

342,983 

June  1, 

r  CCA 
I  OOO. 

G.  L.  Tyler, 
C.  E.  Roberts, 

344.404 

June  29, 

*  CCA 

I  OOO. 

345.007 

July  6, 

1886. 

G.  L.  Tyler, 

346,389 

July  27, 

»  CCA 
I  OOO. 

A.  F.  Stowe, 

347.402 

Aug.  17, 

»  CCA 
I  OOO. 

A.  G.  Webster, 

353.235 

Nov.  23, 

t  CCA 

I  Sou. 

A.  F.  Stowe, 

358,o8l 

Feb.  22, 

1 007. 

T.  Smith, 

358,883 

Mar.  0, 

.00. 
Iooy. 

C.  E.  Roberts, 

362,694 

May  10, 

I  CC-T 

H.  Worcester, 

372,640 

1887. 

C.  E.  Roberts, 

373,196 

Nov.  15, 

1887*. 

C.  E.  Roberts, 

374,401 

Dec.  6, 

1887. 

G.  Faustman, 

378,157 

Feb.  21, 

■  occ 
I  000. 

W.  E.  Adams, 

378,158 

W.  E.  Adams, 

378,179 

S.  Ross,  Jr., 

378,185 

ret).  21, 

*  coo 

I  OOO. 

G.  L.  Tyler, 

378,186 

379,7°° 

Mar.  20, 

» occ 
1 000. 

a.  iiuii. 

3«'.°75 

April  10. 

1  coo 
1 000. 

J.  A.  Josselyn, 

395.759 

Ton  ft 

Jan.  0, 

1  CCn 
I  009. 

H.  Stanley, 

Reissue  \ 
1 1 ,008  / 

June  18, 

1889. 

H.  Stanley, 

403,486 

Mar.  14, 

T  ftftr, 

H.  C.  Pease, 

405,697 

June  25, 

»  ftft^. 
I089- 

E.  M.  Dunphe  and 

C.  Blockhaus, 

4«3.°93 

Oct.  15, 

1889. 

J.  A.  Safford, 

420,152 

Jan.  28, 

1890. 

C.  S.  Fifield, 

445.744 

Feb.  3, 

1891. 

\V.  A.  Bates, 

462,166 

Oct.  27, 

1891. 

J.  A.  Safford, 

465.145 

Dec.  15, 

1891. 

"  " 

477.456 

June  21, 

1892. 

a  tt 

477-457 

it 

"  " 

477,46i 

it  a 

477,462 

a  tt 
S.  H.  Randall, 

479.46i 

fulv  26,  1892. 

5'4,730 

Feb.  13, 

1894. 

J.  A.  Safford, 

537,912 

April  23, 

1895. 

J.  K.  Bigelow, 

539.472 

May  21, 

1895. 

J.  E.  Fairbanks, 

542,740 
554.783 

Julv  16, 

1895. 
1896. 

J.  Robertson, 

Feb.  18, 

M.  Leidgen, 

561,360 

June  9, 

1896. 

T.  J.  Bringham, 

587.783 

Aug.  10, 
Aug.  10, 

1897. 

587,784 

1897. 

G.  R.  Rank, 

588,928 

Aug.  24, 

1897- 

Residence. 
East  Bridgewater,  Mass. 
Olney,  111. 
Peabody,  Mass. 
Boston,  Mass. 
Cleveland,  O. 
Lynn,  Mass. 
Woburn,  Mass. 
Woburn,  Mass. 
Brook  field,  Mass. 
Lynn,  Mass. 
Chicago,  111. 
Lynn,  Mass. 
Worcester,  Mass. 
Boston,  Mass. 
Worcester,  Mass. 
Cincinnati,  O. 
Chicago,  111. 
Maiden,  Mass. 
Chicago,  111. 
Chicago,  111. 
Philadelphia,  Pa. 
Lynn,  Mass. 
Lynn,  Mass. 
Newport,  Ky. 
Lynn,  Mass. 

New  Boston,  Mass. 
Brookfield,  Mass. 
Swampscott,  Mass. 

Swampscott,  Mass. 

Worcester,  Mass. 

East  Bridgewater,Mass. 

Maiden,  Mass. 
Revere,  Mass. 
Princeton,  Me. 
Maiden,  Mass. 


f<  tt 

Wyoming,  O. 
Maiden,  Mass. 
San  Francisco,  Cal. 
Hillsdale,  Mich. 
Woburn,  Mass. 
Milwaukee,  Wis. 
Chicago,  111. 
tt  tt 

Alleghany,  N.  Y. 


Including  machines  used  in  shoe  factories. 


646 


APPENDIX. 


Cutting,  including  Skiving*  etc. 


No. 

Date. 

Inventor. 

Residence. 

296,219 

April  I, 

1884. 

J.  Roth, 

Columbus,  O. 

296,781 

April  15, 

1884. 

C.  E.  Ramus, 

Chicago,  111. 

297>35I 

April  22, 

1884. 

G.  W.  Cody, 

Hartford,  Conn. 

299,329 

May  27, 

1884. 

H.  A.Behn, 

Union,  N.  J. 

299,952 

June  10, 

1884. 

R.  Brownson, 

St.  Paul,  Minn. 

3°2>759 

July  27, 

1884. 

A.  Miller  and  J.  M. 

Newark,  O. 

Kailer, 

304,824 

Sep.  9, 

1884. 

E.  Johnson, 

New  Orleans,  La. 

3°7,I27 

Oct.  28,  1884. 

W.  Lufkin, 

Chelsea,  Mass. 

310,527 

June  6, 

1885. 

H.  E.  Koepka, 

St.  Johnsbury,  Vt. 

3i°>742 

Jan.  13, 

1S85. 

G.  E.  Stock  well, 

Marblehead,  Mass. 

3I2-643 

Feb.  24, 

1885. 

D.  Knox, 

Lynn,  Mass. 

3'3.l67 

Mar.  3, 

1885. 

R.  Bowden, 

Marblehead,  Mass. 

3i3.!72 

« 

it 

N.  \V.  Calhoun  and  J. 

Lena,  111. 

G.  Chambers, 

3 1 3.349 

n 

it 

F.  R.  Lewis, 

Troy,  N.  Y. 

3 1 4.474 

Mar.  24, 

1885. 

T.  M.  Platts, 

Newark,  N.  J. 

3 1 6,006 

April  21, 

1885. 

J.  H.  Busell, 

Boston,  Mass. 

3l6.°73 

C.  F.  Stack  pole, 

Lynn,  Mass. 

316,074 

C.  F.  Stackpole, 

Lynn,  Mass. 

316,704 

April  28, 

1885. 

J.  M.  Watson, 

Sharon,  Mass. 

3 1 7,463 

May  5, 

1885. 

D.  Knox, 

Lynn,  Mass, 

320,209 

June  16, 

1885. 

E.  F.  Belding, 

Fitchburg,  Mass. 

322,923 

July  28, 

1885. 

T.  Gingras, 

Buffalo,  N.  Y. 

323,061 

July  28, 

1885. 

T-  Murphy, 

Brooklyn,  N.  Y. 

323,860 

Aug.  4, 

1885. 

M.  V.  Doyle, 

Rockford,  111. 

325.°37 

Aug.  25, 

1885. 

Abbott  and  Luce, 

Dedham,  Mass. 

328,317 

Oct.  13, 

1885. 

J.  Kirwin, 

New  York  City. 

33I>293 

July  28, 

1885. 

T.  Gingras, 

Buffalo,  N.  Y. 

334,H9 

Jan.  12, 

1886. 

J.  D.  Hunphrey, 

Towanda,  Pa. 

338,347 

Mar.  23, 

1886. 

C.  T.  Grilley, 

Boston,  Mass. 

343,238 

June  8, 

1886. 

H.  G.  Foss, 

Auburn,  Me. 

346,093 

July  27, 

1886. 

H.  H .  Cummings, 

Maiden,  Mass. 

346,651 

Aug.  1, 

1886. 

G.  W.  Cross, 

Oxford,  N.  J. 

35°>753 

Oct.  12, 

1886. 

E.  A.  Latham, 

East  Bridgewater.Mass. 

352,139 

Nov.  9, 

1886. 

J.  Leuenberger, 

Camden,  0. 

356,662 

Jan.  25, 

1887. 

T.  B.  Raymond, 

Rochester,  N.  Y. 

356.793 

Feb.  1, 

1887. 

J.  W.  Ringrose,  and 
D.  A.  Hauck, 

Mechanicsburg,  111. 

358,067 

Feb.  22, 

1887. 

J.  Parker  and  N.  L. 
( 'lunning. 

Williamsport,  Pa. 

358,779 

Mar.  1, 

1887. 

N.  B.  Jones, 

Murfreesboro,  111. 

361,707 

April  26, 

1887. 

J.  Matthieu, 

Ottawa,  111. 

362,412 

May  3, 

1887. 

W.  E.  Adams, 

Lynn,  Mass. 

363,265 

May  17, 

1887. 

J.  N.  Whitcomb, 

Brockton,  Mass. 

363,461 

May  24, 

1887. 

C.  B.  Hatfield, 

Rochester,  N.  Y. 

364,643 

June  14, 

1887. 

A.  D.  Goetz, 

Martinsburg,  Pa. 

367,709 

Aug.  2, 

1887. 

F.  Engel  and  C.  Wagner, 

Offenbach  on  Main,Ger. 

368,108 

Aug.  8, 

1887. 

H.  Parsons, 

Marlboro,  Mass. 

368,672 

Aug.  23, 

1887. 

W.  C.  James, 

Boston,  Mass. 

37°-327 

Sept.  20, 

1887. 

W.  S.  Fitzgerald, 

Boston,  Mass. 

373,i26 

Nov.  15, 

1887. 

J.  Burger, 
G.  Marsh, 

Cincinnati,  O. 

375,372 

Dec.  27, 

1887. 

Nashville,  Tenn. 

375,8n 

Jan.  3, 

1888. 

E.  Gott, 

Newton,  Mass. 

376,974 

Jan.  24, 

1888. 

C.  Wonderlich, 

Washington,  Mo. 

Including  machines  u^ed  in  shoe  factories. 


APPENDIX. 


647 


No. 

Date. 

Inventor. 

381,696 

April  24, 

[888. 

F.  Hirsch, 

384,020 

June  5, 

[888. 

P.  B.  Clark  and  G.  J. 

Klingler, 

384.032 

June  5, 

1888. 

F.  E.  Frost, 

386,051 

July  10, 

[888. 

G.  H.  Avery, 

390,551 

Oct.  2, 

1888. 

E.  F.  Belding, 

391,190 

Oct.  16, 

1888. 

S.  H.  Randall, 

391.575 

Oct.  23, 

888. 

C.  H.  Bayley, 

392,673 

Nov.  13, 

[888. 

A.  D.  Goetz, 

394.1 1 1 

Dec.  4, 

[888. 

O.  G.  Garlock, 

399,965 

Mar.  19, 

1889. 

J.  Bradley, 

403,805 

May  zi, 

[889. 

S.  Walder, 

404,949 

June  11, 

1889. 

G.  H.  Avery, 

412,503 

Oct.  8, 

[889. 

W.  H.  Hoople, 

417,268 

Dec.  17, 

[889. 

J.  G.  McCartee, 

419.357 

Jan.  14, 

1890. 

C.  E.  Ramus, 

421,778 

Feb.  18, 

1890. 

II.  G.  Starr, 

423,977 

Mar.  25, 

[890. 

A.  D.  Worthen, 

426,251 

April  22, 

1890. 

G.  F.  Dunn, 

426,577 

April  29, 

1890. 

V.  T.  Whittlesey  and 

A.  B.  Keyes, 

427,461 

May  6, 

[890. 

H.  Comstock, 

427,579 

May  13, 

[890. 

F.  L.  Kulin, 

427,610 

May  13, 

1890. 

H.  C.  Pretty, 

430,882 

June  24, 

1890. 

J.  O.  Purnell, 

432,641 

Feb.  22, 

[890. 

C.  E.  Ramus, 

435,38i 

Aug.  26, 

1890. 

H.  T.  Rohrmoser, 

439.2o8 

Oct.  28, 

1890. 

A.  J.  Tewksbury, 

439,433 

Oct.  28, 

1890. 

J.  R.  Scott, 

439,6o3 

Oct.  28, 

1890. 

Randall. 

442,399 

Pec.  9, 

1890. 

J.  A.  Safford, 

442,990 

May  26, 

1 891. 

B.  F.  Durham, 

443,579 

Dec.  30, 

1890. 

S.  Hainkel, 

443,40<) 

Dec.  23, 

[890. 

J.  R.  Scott, 

445,588 

Feb.  3, 

1 891, 

H.  C.  Pease, 

453.944 

June  9, 

1 891. 

J.  R.  Scott, 

458,535 

Aug.  25, 

1 891. 

VV.  H.  Kimball, 

459,231 

Sept.  8, 

1 891. 

C.  S.  Fifield, 

459,715 

Sept.  15, 

1 891. 

S.  J.  Talbott, 

465,840 

Dec.  29, 

1 891. 

A.  Devvees  and  R.  P. 

Trist, 

467,441 

Jan.  19, 

1892. 

J.  R.  Scott, 

468,613 

Feb.  9, 

1892. 

R.  P.  Trist, 

470,015 

Mar.  1, 

1892. 

J.  R.  Scott, 

470,016 

" 

" 

472,148 

April  5, 

1892. 

A.  J.  Tewksbury, 

475>05" 

May  17, 

1892. 

L.  M.  Cabana, 

477,458 

June  21, 

1892. 

J.  A.  Safford, 

477-459 

/  '     t  T     Ti        l  , 

(_.  rl.  riayley, 

479,583 

July  26, 

1892. 

486,813 

Nov.  22, 

1892. 

A.  K.  Washburn, 

487,894 

Dec.  13, 

1892. 

J.  H.  Shields, 

488,21 2 

Dec.  20, 

1892. 

H.  Masterson, 

488,324 

Dec.  20, 

1892. 

P.  VV.  Rodecker, 

492,342 

Feb.  21, 

1893. 

T.  F.  Tyler, 

492,640 

Feb.  28, 

i893- 

T.  Thompson, 

493,i89 

Mar.  7, 

1893. 

J.  L.  Scott, 

Residence. 
New  York  City. 
Brooklyn,  N.Y. 

Lewiston,  Me. 
East  Hampton,  Mass. 
Fitchburg,  Mass. 
Wyoming,  O. 
Boston,  Mass. 
Martinsburg,  Pa. 
Palmyra,  N.  Y. 
Dundee,  N.  Y. 
Buda-Pesth,  Hungary. 
East  Hampton,  Mass. 
Brooklyn,  N.  Y. 
Boston,  Mass. 
Chicago,  111. 
Belvedere,  111. 
Sandown,  N.  H. 
Brockton,  Mass. 
New  Haven,  Conn. 

Fulton,  N.  Y. 
Lunenburg,  Mass. 
Leicester,  England. 
Pittsfield,  Mass. 
Chicago,  111. 
Hoboken,  N.  J. 
Haverhill,  Mass. 
Nyack,  N.  Y. 

Maiden,  Mass. 
Brockton,  Mass. 
Ouincy,  111. 
Nyack,  N.  Y. 
Worcester,  Mass. 
New  York  City, 
Burlington,  N.  J. 
Revere,  Mass. 
Milford,  N.  H. 

Brooklyn,  N.  Y. 
New  York  City. 
Wilmington,  Del. 
New  York  City. 
a 

Haverhill,  Mass. 
Buffalo^  N.  Y. 
Maiden,  Mass. 

Boston,  Mass. 
Bridgewater,  Mass. 
Chicago,  111. 
Jefferson  City,  Mo. 
Sidney,  O. 
Lynn,  Mass. 
New  London,  Wis. 
New  York  City. 


648  APPENDIX. 


No. 

Date. 

Inventor. 

Residence. 

500,538 

July  4. 

1893. 

A.  J.  Allen, 

Essex,  Canada. 

501,207 

Sept.  11, 

1893- 

T.  Gingras, 

Buffalo,  N.  Y. 

503.341 

Aug.  15, 

1893. 

M.  E.  Briggs, 

St.  Louis,  Mo. 

505,198 

Sept.  19, 

[893- 

C.  S.  Fifield, 

Revere,  Mass. 

505,598 

Sept.  26, 

1893- 

r-/          '!>         f—                      1                          1  ITT 

Z.  I.  trench  and  W. 

Boston,  Mass. 

T.  Meyer, 

506,573 

Oct.  10, 

893- 

J.  M.  Watson, 

Sharon,  Mass. 

507,210 

Oct.  24, 

893- 
894. 

A.  Buchholz, 

Boeuf  Creek,  Mo. 

5 1 2.953 

Jan.  16, 

J.  Gerber, 

Tremont,  Mich. 

5 1 5.927 

Mar.  6, 

[894. 

E.  B.  Stimpson, 

Brooklyn,  N.  Y. 

5i7-63i 

April  3, 

[894. 

A.  J.  Tewksbury, 

Haverhill,  Mass. 

518.774 

April  24, 

894. 

G.  H.  Bayley, 

Boston,  Mass. 

518,790 

April  24, 

1894. 

A.  E.  Perry, 

11T     1       f     11  H( 

Wakefield,  Mass. 

5r9.57° 

May  8, 

[894. 

IT       ■      t~-v      j                  1  til 

H.  A.  Dodge  and  W. 

Newton,  Mass. 

T.  Richards, 

520,215 

May  22, 

[894. 

T.  A.  Norris, 

Brockton,  Mass. 

520,709 

May  29, 

[894. 

J.  R.  Scott, 

New  York  City. 

520,851 

June  5, 

[894. 

J.  K.  and  O.  Kempfe, 

Brooklyn,  N.  Y. 

521,048 

June  5, 

[894. 

M.  J.  Ryan, 

New  Orleans,  La. 

521,068 

June  5, 

1894. 

H.  Wright, 

Kettering,  England. 

521,077 

June  5, 

1894. 

J.  Barker, 

Philadelphia,  Pa. 

521,090 

June  5, 

[894. 

j.  R.  Scott, 

New  York  City. 

521,538 

June  19, 

[894. 

P.  Goldstein, 

Newark,  N.  J. 

521,583 

June  19, 

1894. 

G.  A.  Cole  and  E.  H. 

Lynn,  Mass. 

Taylor, 

525,872 

Sept.  11, 

1894. 

E.  B.  Stimpson, 

Brooklyn,  N.  Y. 

524,768 

June  21, 

1894. 

Randall. 

526,617 

Sept.  25, 

1894. 

F.  E.  Druschkey  and 

Chicago,  111. 

L.  A.  Schyerling, 

527,299 

Oct.  9, 

1894. 
1894. 

F.  L.  Stone, 

Brockton,  Mass. 

527.928 

Oct.  23, 

C.  H.  Bayley, 

Boston,  Mass. 

528,448 

Oct.  30, 

1894. 

J.  R.  Scott, 

New  York  City. 

528,502 

Oct.  30, 

1894. 

W.  E.  Bennett, 

Boston,  Mass. 

531,069 

Dec.  18, 

1894. 

L.  K.  Scotford, 

^  -1     '   Til 

Lnicago,  ill. 

531,744 

Jan.  1, 

[895. 

T.  A.  Norris, 

Brockton,  Mass. 

531.949 

Jan.  1, 

1895- 

J.  N.  Kendall, 

Nashua,  N.  H. 

534,767 

Aug.  21, 

1894. 

Randall. 

535.784 

Mar.  12, 

1895. 

L.  T.  Barber, 

Boston,  Mass. 

535.895 

Mar.  19, 

1895. 

B.  F.  Hale, 

Newburyport,  Mass. 

537.148 

April  9, 

1895. 

J.  B.  Gathright, 

Louisville,  Ky. 

537.913 

April  23, 

1895. 

J.  K.  Bigelow, 

San  Francisco,  Cal. 

541,304 

June  18, 

1895- 

P.  Young, 

Danbury,  Conn. 

541,691 

June  25, 

1895. 

J.  R.  Scott, 

New  1  ork  City. 

543,635 

July  30, 

1895. 

A.  S.  Vose, 

Providence,  R.  I. 

543,792 

July  30, 

I895- 

R.  Wright  and  J.  E. 

Chicago,  111. 

Parker, 

548,101 

Oct.  15, 

1895. 

S.  Ward, 

Princeton,  Ind. 

549,027 

Oct.  29, 

1 895. 

J.  R.  Scott, 

Chicago,  111. 

549,216 

Nov.  5, 

1895. 

E.  Sawver, 

Barre  Vt. 

550,805 

Dec.  3, 

1895. 

E.  Stimpson. 

Dec.  24, 

I895- 

W.  A.  Murray  and  H. 

Newark,  N.  J. 

Fitzsimmons, 

554.o69 

Feb.  4, 

1896. 

L.  H.  Liebe  and  J.  A. 

San  Jose,  Cal. 

Vanderpool, 

557>276 

Mar.  31, 

1896. 

W.  B  Keighley, 

Vineland,  N.  J. 

557.554 

April  7, 

1896. 

E.  V.  Clemens, 

New  York  City. 

APPENDIX. 


No. 

Date. 

Inventor. 

558,864 

April  21,  1896. 

E.  Van  Osla, 

560,782 

May  26,  1896. 

J.  Crydermann, 

561,999 

June  16,  1896. 

W.  Kootz, 

562,000 

" 

W.  Kootz, 

562,126 

H.  Ellis, 

564,889 

July  28,  1896. 

E.  Rahm, 

S67.'3° 

Sep.    0,  1890. 

r.  Goldstein  and  G. 
Andae, 

567.i3i 

Sep.    8,  1896. 

P.  Goldstein  and  G. 
Andae, 

570,164 

Oct.  27,  1896. 

K.  J.  Freese, 

571.291 

Nov.  10,  1896. 

A.  L.  Sweet, 

571,292 

5  7 '.293 

a  it 

571.295 

573.274 

Dec.  15,  1896. 

H.  Le  Roy  Kemp, 

575.821 

Jan.  26,  1897. 

H.  F.  Blake, 

578,547 

Mar.   9,  1897. 

E.  F.  Davenport, 

580,390 
586,308 

April  13,  1897. 

J.  H.  Giffard, 

July  13,  1897. 

B.  F.  Dunham, 

Putting  Out  and  Stretching. 


No. 

Date. 

Inventor. 

308,!7I 
318,820 

Nov.  18, 

1884. 

R.  S.  Jennings, 

June  26, 

1885. 
1885. 

Stone  and  Pratt, 

331.325 

Dec.  1, 

B.  M.  Plummer, 

352,024 

Nov.  2, 

(886. 

P.  A.  Jesson, 

Reissue  ) 
10,860  | 

Aug.  23, 

887. 

P.  A.  Jesson, 

378,066 

Feb.  14, 

888. 

W.  M.  Hoffman, 

387.305 

Aug.  7, 

888. 

J.  F.  Ingraham, 

387,402 

Aug.  7, 

888. 

G.  E.  Danforth, 

388,611 

Aug.  28, 

[888. 

W.  E.  Adams, 

392,141 

Oct.  30, 

888. 

N.  Weber, 

393.544 

Nov.  27, 

888. 

P.  H.  Daley, 

395,727 

Jan.  8, 

[889. 

N.  Weber, 

396,811 

Jan.  29, 

1889. 

( ;.  E.  Danforth, 

397.821 

Feb.  12, 

889. 

F.  Storch, 

402,860 

May  7, 

889. 

C.  T.  Royer, 

416,918 

Dec.  10, 

889. 

M.  N.  Howard, 

423.030 

Mar.  11, 

1890. 

G.  E.  Danforth, 

423,846 

Mar.  18, 

[890. 

West  and  Sinning 

457.U6 

Aug.  4, 

[891. 

C.  R.  Stackpole, 

457.331 

Aug.  4, 

(891. 

G.  V.  Anderson, 

501,593 

July  18, 

(893- 

C.  R.  Stackpole, 

538,914 

May  7, 

[895. 

R.  Holmes, 

549,422 

Nov.  5, 

1895- 

G.  W.  Baker, 

549,423 

Nov.  5, 

[895. 

G.  W.  Baker, 

549,424 

Nov.  5, 

1895. 

G,  W.  Baker, 

553,682 

Jan.  25, 

1896. 

L.  Lichtenstein, 

553,683 

Jan.  25, 

1896. 

L.  Lichtenstein, 

580,865 

April  20, 

1897. 

G.  V.  Hysore, 

582,774 

May  18, 

1897. 

C.  Bouteon, 

585,212 

Jan.  29, 

1897. 

A.  F.  Jones, 

649 

Residence. 
Louisville,  Ky. 
Milwaukee,  Wis. 

ti  tt 
St.  Catherines,  Can. 
Elberfeld,  Germany. 
Newark,  N.  J, 

Newark,  N.  J. 

Montreal,  Canada. 
Chicago,  111. 


Camden,  N.  J. 
Haverhill,  Mass. 
Boston,  Mass. 
Grand  Rapids.  Mich. 
Brockton,  Mass. 


Residence. 
Boston,  Mass. 
Salem,  Mass. 
Philadelphia,  Pa. 
Paris,  France. 

Paris,  France. 

Detroit,  Mich. 
West  Peabody,  Mass. 
Lynn,  Mass. 
Lynn,  Mass. 
Lynn,  Mass. 
Lynn,  Mass. 
Lynn,  Mass. 
Lynn,  Mass. 
Chicago,  111. 
Halifax,  England. 
Brooklyn,  N.  Y. 
Lynn,  Mass. 
St.  Louis,  Mo. 
Lynn,  Mass. 
Wilmington,  Del. 
Lynn,  Mass. 
Cramer's  Hill,  N.  J. 
Wilmington,  Del. 
Wilmington,  Del. 
Wilmington,  Del. 
Wilmington,  Del. 
Wilmington,  Del. 
Wilmington,  Del. 
Paris,  France. 
Salem,  Mass. 


650 


No. 
308, 1 70 

335-595 
357.609 
372,228 
410,745 
414,283 
440,358 
44*3,794 
446,847 
468,392 

484,137 
490,338 
490,339 
501,920 

5 1 3,943 
536,456 
546,089 


No. 

299,893 
305,532 
313,231 
325.675 

340,713 
343,552 
354,178 
363.585 
372,507 
380,239 
391,221 
394,750 
405,653 
426,225 
441,821 
443,896 
451,096 
479,460 
484,029 
486,194 

490,443 
531,462 
546,263 
559,976 
561,583 
569,843 
589.123 


No. 
333.196 
339.134 
346,900 


APPENDIX. 


Stretching  Frames. 


Date. 

Inventor. 

Residence. 

Nov.  18,  1884. 

R.  S.  Jennings, 

Boston,  Mass. 

Feb,   9,  1886. 

A.  C.  Krueger, 

Chicago,  111. 

Feb.  15,  1887. 

H.  G.  Landers, 

Protem,  Mo. 

Dec.   6,  1887. 

J.  Young, 

Newark,  N.  J. 
Newark,  N.  J. 

Sept.  10,  1889. 

G.  F.  Stengel, 

Nov.  5,  1889. 

B.  P.  Bradford. 

Worcester,  Mass. 

Nov.  11,  1890. 

P.  King, 

Washington,  D.  C. 

PVk        ft  iftr»¥ 

rcU.    0,  1 09 1. 

W.  Coupe, 

Attleboro,  Mass. 

Feb.  24,  1 89 1. 

H.  R.  Behrens, 

Worcester,  Mass. 

Feb.    9,  1892. 

H.  R.  Behrens, 

Worcester,  Mass. 

Oct.  11,  1892. 

L.  F.  Cauffield, 

Ashtabula,  O. 

Jan.  24,  1893. 

L.  F.  Cauffield, 

Ashtabula,  0. 

Jan.  24,  1893. 

L.  F.  Cauffield, 

Ashtabula,  0. 

July  25,  1893. 

J.  M.  Charnock, 

Boston,  Mass. 

Jan.  30,  1894. 

P.  King, 

Washington,  D.  C. 

Mar.  26,  1895. 

J.  W.  Chapman, 

Detroit,  Mich. 

Sept.  10,  1895. 

Cook  and  Houston, 

San.  Francisco,  Cal. 

Reciprocating  Tools. 


Date. 

Inventor. 

Residence. 

June  3, 

1884. 

W.  H.  Wood, 

Woburn,  Mass. 

Sep.  23, 

1884. 

J.  A.  Panton, 

Quincy,  Mass. 

Mar.  3, 

1885. 

J.  A.  Panton, 

Quincy,  Mass. 

Sep.  8, 

1885. 

S.  Haley, 

Bramley,  Leeds,  Eng- 

land. 

April  27, 1 886. 

J.  T.  Freeman, 

Woburn,  Mass. 

June  8, 

1886. 

Tyghe  and  Howell, 

Boston,  Mass. 

Dec.  14, 

1886. 

A.  M.  Bowers, 

Newark,  N.  J. 

May  24, 

1887. 

A.  M.  Bowers, 

Newark,  N.  J. 

Nov.  1, 

1887.  • 

G.  W.  Baker, 

Wilmington,  Del. 

Mar.  27, 

1888. 

G.  V.  Anderson, 

Oct.  15, 

1888. 

G.  V.  Anderson, 

Dec.  18, 

1888. 

G.  W.  Baker, 

June  18, 

1889. 

G.  W.  Baker, 

April  22, 

1890. 

G.  W.  Anderson, 

Dec.  2, 

1890. 

J.  A.  Brownwell, 

Binghamton,  N.  V. 

Dec.  30, 

1890. 

B.  D.  Chalkley, 

Richmond,  Va. 

April  28,  1 89 1. 

P.  W.  Whittier, 

North  Andover,  Mass, 

July  26, 

1892. 

O.  Potelune, 

Limoges,  France. 

Oct.  11, 

1892. 

L.  E.  Learoyd, 

Danvers,  Mass. 

Nov.  15, 

1892. 

P.  W.  Minor, 

Springville,  N.  Y. 

Jan.  24, 

1893- 

F.  C.  Kimball, 

Salem,  Mass. 

Dec.  25, 

1894. 

G.  Geyer, 

Brooklyn,  N,  Y. 

Sep.  10, 

1895. 

I.  Vaughn, 

Salem,  Mass. 

May  12, 

1896. 

T.  Hall, 

Leeds,  England. 

June  9, 

1896. 

J.  Hall. 

Leeds,  England. 

Oct.  20, 

1896. 

H.  Smith, 

Newark,  N.  J. 

Aug.  31, 

1897. 

E.  T.  Ems, 

Philadelphia,  Pa. 

Rocking  Frames. 

Date.                         Inventor.  Residence. 

Dec.  29,  1885.          E.E.  Church,  Beddington,  Me. 

April  6,  1886.           A.  M.  Bowers,  Newark,  N.  J. 

Aug.  10,  1886.          P.  Diehl,  Gloversville,  N.  J. 


APPENDIX.  651 


No. 

Date. 

Inventor. 

Residence. 

365,963 

July  5. 

1887. 

A.  M.  Bowers, 

Newark,  N.  J. 

366,298 

July  1 2, 

1 007. 

"j6t  nc? 

Aug.  9, 

1887. 

392,004 

Oct.  30, 

1888. 

«  « 

11  ii 

437,483 

■  Sep.  30, 

1890. 

T.  P.  Combs, 

Woburn,  Mass. 

448,422 

Mar.  17, 

1891. 

Oafney  and  Dawson, 

Lynn,  Mass. 

556,162 

Mar.  10, 

1896. 
1897. 

T.  J.  Quinn, 

Stoncham,  Mass. 

589,103 

Aug.  31, 

C.  A.  Southwick, 
Rotating  Tools. 

Peabody,  Mass. 

No. 

Date. 

Inventor. 

Residence. 

292,723 

Jan.  29, 

1884. 

A.  Winchester, 

Rochester,  N.  V. 

3°6,737 

Aug.  21, 

1884. 

M.  Garniel, 

Paris,  France. 

387,903 

Aug.  14, 

1888. 

A.  Ott, 

Milwaukee,  Wis. 

427,101 

May  6, 

1890. 

P.  Monk, 

Cincinnati,  O. 

444,164 

Jan.  6, 

1891. 

J.  W.  Vaughn, 

Salem,  Mass. 

4.6"?.  S02 

Nov.  17, 

1891. 

W.  S.  Bacon, 

Philadelphia,  Pa. 

489,641 

Jan.  10, 

1893- 

A.  Probst, 

Worms.  Germany. 

491,446 

Feb.  7, 

1893- 

Pullman  and  Smith, 

Godalming,  England. 

5 '7,424 

Oct.  16, 

1894. 

Ilartman  and  Thomson, 

Offenbach  on  Main.Ger. 

527,889 

Oct.  23, 

1894. 

L.  and  A.  Schmoll, 

Newark,  N.  J. 

564,511 

July  2 1 , 

1896. 

E.  D.  Evans, 
Rotary  Cylinders. 

Bristol,  Eng. 

No. 

Date. 

Inventor. 

Residence. 

293,308 

Feb.  12, 

1884. 

A.  Ceif.  Lanzenburg, 

Paris,  France. 

316,167 

April  21, 

1885. 

F.  J.  Nelson, 

Boston,  Mass. 

317,770 

May  12, 

1885. 

G.  A.  Hardy, 

Old  Lenton,  England. 

325,431 

Sept.  1, 

1S85. 

V.  H.  Meyers, 

Philadelphia,  Pa. 

327>'38 

Sept.  20, 

1885. 

H.  R.  Churchill, 

Buffalo,  N.  Y. 

335>'98 

Feb.  2, 

1886. 

W.  M.  Hoffman, 

Buffalo,  N.  Y. 

367,257 

[uly  26,  1887. 

A.  E.  Whitney, 

Winchester,  Mass. 

372,585 

Nov.    1 , 

1887. 

J.  Wayland, 

Newark,  N.  J. 

377,473 

Feb.  7, 

1888. 

G.  V.  Anderson, 

Wilmington,  Del. 

386,667 

Jan.  26, 

1888. 

II.  Thurlow, 

Skaneateles,  N.  Y. 

413,601 

Oct.  22, 

1889. 

H.  E.  Freudenberg, 

Wenheim,  Baden,  Ger. 

417,251 

Dec.  17, 

1889. 

Klinik,  Penkowski  and 

Konigshutte,  Germany. 

Gross, 

430,165 

June  17, 

1890. 

A.  C.  Andrews, 

Chicago,  111. 

449,707 

April  7, 

1891. 

T.  Shaw, 

Vanceboro,  Me. 

451,486 

May  5, 

1891. 

A.  K.  Huiting, 

Salem,  Mass. 

466,182 

Dec.  29,  1891. 

E.  <  .  Northrup, 

Bodines,  Pa. 

5°7'3H 

Oct.  24, 

1893- 

W.  Evans, 

Philadelphia,  Pa. 

525,372 

Sept.  4, 

1894. 

I.  Vaughn, 

Salem,  Mass. 

535-493 

Sept.  4, 

1894. 

W.  Evans, 

Philadelphia,  Pa. 

577,402 

Feb.  16, 

1897. 

H.  Bright, 

Costello,  Pa. 

580,353 

April  6, 

1897. 

I.  Vaughn, 

Salem,  Mass. 

Rolling  and  Embossing. 

No. 

1  >ate. 

Inventor. 

Residence. 

294,410 

Mar.  4, 

1884. 

T.  Shaw, 

Bangor,  Me. 

295,948 

April  1, 

1884. 

W.  A  Sawyer, 

Danversport,  Mass. 

310,160 

Dec.  30, 

1884. 

W.  C.  Yaeger, 

Brownstown,  Wis. 

311,498 

Feb.  3, 

1885. 

D.  Knox, 

Lynn,  Mass. 

312,272 

Feb.  17, 

1885. 

W.  W.  Hubbard, 

Manchester,  N.  H. 

65  2 

Arl  iiJN  Dl\ . 

No. 

Date. 

Inventor. 

Residence. 

337,935 

April  13,  1886. 

A.  M.  Bowers. 

Newark,  N.  J. 

356,677 

Jan.  25, 

I0O7. 

J.  Boyle, 

Peabody,  Mass. 

393,486 

Jan.  27, 

1888. 

M.  Scott, 

Newark,  N.  J. 

444,172 

Oct.  6, 

I89I. 

J.  W.  Vaughn, 

Salem,  Mass. 

447,180 

Feb.  24, 

189I. 

E.  Hayes, 

Lynn,  Mass. 

466,083 

Dec.  29, 

189I. 

J.  A.  Safford, 

Maiden,  Mass. 

462,825 

Nov.  10, 

189I. 

M.  Scott. 

Newark,  N.  J. 

479,400 

June  21, 

1892. 

|.  odiioru, 

\/[  ilrlon      AT  ice 
LViaiUCll,    1*1  d.33. 

C  C2  8C7 

Jan.  7, 

1896. 

M.  Scott, 

Newark.  N.  J. 

J  (testes  uilti  fiLllrlts, 

No. 

Date. 

Inventor. 

Residence. 

291,882 

Jan.  15, 

1884. 

T.  L.  Daheny, 

Boston,  Mass. 

333.773 

Jan.  5, 

1886. 

G.  Middlemas, 

San  Francisco,  Cal. 

340,712 

April  27, 

1886. 

J.  T.  Freeman, 

Woburn,  Mass. 

352'955 

Nov.  23, 

1886. 

1 .  W.  Mch.ee, 

1  owanda,  ra. 

362,286 

May  3, 

1887. 

G.  A.  Knox, 

Lynn,  Mass. 

457,014 

Aug.  4, 

I89I. 

B.  Schnepp, 

Louisville,  Ky. 

547,70.2 

Oct.  15, 

I895. 

Ml 1 »'  H  1,1,  \JCI  111  all  V . 

584,668 

June  15, 

1897. 

J.  A.  Brownell, 

Binghamton,  N.  Y. 

/  //  ill  /}  1 }  11  <Y  ffi'JJJUC 

1  a  ftiu it       j-s /  ftffij. 

No. 

Date. 

Invenlor. 

Residence. 

302,454 

July  22, 

1884. 

E.  S.  Ward, 

Newark,  N.  J. 

308,755 

Dec.  2, 

I884. 

E.  D.  Solminehac, 

Lorient,  Prance. 

3I3.478 

Mar.  10, 

1885. 

J.  Davis, 

Allegheny,  Pa. 

Mar.  10, 

1885. 

L.  Simpson, 

Pittsburg,  Pa. 

313,543 

Mar.  10, 

I885. 

Simpson  and  Davis, 

Pittsburg,  Pa. 

3H,i99 

Mar.  17, 

I885. 

L.  Simpson, 

Pittsburg,  Pa. 

314,200 

385.644 

July  3. 

1888. 

W.  Schweickhardt, 

St.  Louis,  Mo. 

421,249 

Feb.  11, 

189O. 

A.  J.  Darragh, 

Allegheny  City,  Pa. 

461,019 

Oct.  13, 

189I. 

G.  Hulseman, 

Cincinnati,  O. 

497.95 1 

May  23, 

I893- 

J.  Davis, 

Allegheny  City,  Pa. 

Hides,  Skins  and  Leather. 


No. 

Date. 

Inventor. 

Residence. 

343.247 

Aug.   6,  1886. 

E.  B.  Light, 

Denver,  Col. 

363.546 

May  24,  1887. 

C.  A.  Schieren, 

Brooklyn,  X.  V. 

381,932 

May    1,  1888. 

C.  M.  Kimball, 

Haverhill,  Mass. 

38l,933 

a  a 

393.845 

Dec.   4,  1888. 

G.  P.  McMahon, 

Pawtucket,  R.  I. 

400,443 

April  12,  1889. 

C.  W.  Cooper, 

Brooklyn,  N.Y. 

408,896 

Aug.  13,  1889. 

P.  Latulip, 

Syracuse,  N.  Y. 

451,796 

May    5,  1891. 

G.  W.  Baker, 

Wilmington,  Del. 

478,499 

July    5,  1892. 

T.  Burns, 

Edinburgh,  Scotland. 

487,067 

Nov.  29,  1892. 

J.  W.  Deckert, 

Newark,  N.  J. 

578,257 

Mar.  2,  1897. 

McKenzie  and  Shaw, 

Cheboygan,  Mich. 

Leather 

Working  Machinery. 

No. 

Date. 

Inventor. 

Residence. 

294,320 

Feb.  26,  1884. 

J.  H.  Hovey, 

Woburn,  Mass. 

294,394 

Mar.  4,  1884. 

R.  H.  I.ufkin, 

Chelsea,  Mass. 

297,260 

Apr.  22,  1884. 

A.  Heim, 

New  York  City. 

APPENDIX. 


No. 

Date. 

Inventor. 

Residence. 

300,812 

June  24,  1884. 

S.  S.  Spear, 

South  Weymouth,Mass. 

328,078 

Oct.  13,  1885. 

A.  F.  Stowe, 

Worcester,  Mass. 

342,193 

May  18,  1886. 

C.  S.  Fifield, 

Revere,  Mass. 

370,068 

Sep.  20,  1887. 

F.  Knox, 

Boston,  Mass. 

380,157 

June  17,  1888. 

J.  J.  and  G.  J.  Daley, 

Brooklyn,  N.  Y. 

388,419 

Aug.  28,  1888. 

D.  Knox, 

Lynn,  Mass. 

392,U3 

(Jet.  3°,  1888. 

W.  Foglesong, 

Dayton,  O. 

402,060 

A|>r.  23,  1889. 

M.  Brock, 

Boston,  Mass. 

402,061 

402,062 

402,069 

Apr.  23,  1889. 

J.  A.  Crosbie, 

Methuen  Mass. 

404,904 

June  11,  1889. 

C.  S.  Gooding  and  S. 

w .  Laud, 

11           111  ¥f 

rirookline,  Mass. 

425,935 

Apr.  15,  1890. 

F.  Bain, 

Chicago,  111. 

43', 549 

July    8,  1890. 

M.  Brock, 

Boston,  Mass. 

43I.561 

July    8,  1890. 

J.  A.  Crosbie, 

Methuen,  Mass. 

453,141 

May  26,  1 89 1. 

M.  Brock, 

Boston,  Mass. 

579,468 

June  23,  1897. 

F.  J.  Bringham, 

Chicago,  111. 

Tanners'  Tools. 

IN  0. 

Date. 

Inventor. 

Residence. 

346,487 

.Aug.    3,  I886. 

A.  V.  Manly, 

Norwich,  X.  V. 

361,176 

Apr.  12,  1887. 

J.  McDermott, 

Middletown,  N.  Y. 

Nov.  22,  1887. 

it 

427,555 

May  13,  1890. 

P.  S.  Connor, 

Lake,  111. 

440,240 

i>  o\ .  ii,  1  oyo. 

ix.  n.  nouk, 

Morris,  111. 

^,-|,724 

Jan.  13,  1891. 

H.  B.  Bryant, 

Manchester,  N.  H. 

464.493 

Dec.   8,  1 89 1. 

H.  L.  Clark, 

Canton,  Pa. 

470,872 

Mar.  15,  1892. 

B.  Schnepp, 

Louisville,  Ky. 

51  I.300 

Dec.  19.  1893. 

W.  F.  Lawley, 

Kennedy,  Ala. 

511,521 

Dec.  26,  1893. 

O.  Geisler, 

G  lovers ville,  N.  Y. 

Helical  Tools. 

XT.. 
XNO. 

Date. 

Inventor. 

Residence. 

299,701 

June    3,  1884. 

J.  W.  Vaughn, 

Peabody,  Mass. 

310,279 

Jan.     6,  1885. 

W.  M.  Hoffman, 

Buffalo,  N.  Y. 

311,582 

Feb.    3,  1885. 

J.  Hodskinson, 

Salem,  Mass. 

323,334 

July  28,  1885. 

W.  M.  Hoffman, 

Buffalo,  N.  Y. 

330,655 

Nov.  17,  1885. 

A.  E.  Whitney, 

Winchester,  Mass. 

335.'97 

Feb.    2,  1886. 

W.  M.  Hoffman, 

Buffalo,  N.  Y. 

339,323 

April  6,  1886. 

J.  Rood, 

Salem,  Mass. 

341,977 

May    8,  1886. 

A.  E.  Whitney, 

Winchester,  Mass. 

344,068 

June  22,  1886. 

J.  W.  Vaughn, 

Peabody,  Mass. 

344,069 

■  " 

363,295 

May  17,  1887. 

Lichtenburg  and  Ba- 

louin, 

Milwaukee,  Wis. 

373>112 

.NOV.  15,  1007. 

J.    VV .    V  dUgllll, 

Peabody,  Mass. 

382,262 

May    1,  1888. 

J.  Hodskinson, 

Salem,  Mass. 

383,9 '4 

june    5,  1000. 

Rood  and  Vaughn, 

Oaleiil,  lVld.S>3. 

401,905 

April  23,  1889. 

J.  Rood, 

Salem,  Mass. 

425,112 

April  8,  1890. 

[.  Straiton, 

Bootle,  England. 

456,421 

July  21,  1891. 

M.  and  V.  Martin, 

Paris,  France. 

462,838 

Nov.  10,  1891. 

W.  Evans, 

Philadelphia,  Pa. 

44i,i73 

Jan.     6,  1891. 

J.  W.  Vaughn, 

Peabody,  Mass. 

484.146  | 

484.147  | 

Oct.  11,  1892. 

W.  Evans, 

Philadelphia,  Pa. 

654 


APPENDIX. 


No. 

Date. 

Inventor. 

Residence. 

467,216 

Jan.  19, 

1892. 

A.  E.  Whitney, 

Winchester,  Mass. 

473.039 

(i 

u  « 

CI  tt 

494.183 

Mar.  28,  1893. 

tt  it 

tt  tt 

497.941 

May  23, 

1893. 

G.  W.  Baker, 

Wilmington,  Del. 

5°9>5°3 

Nov.  28, 

1893. 

A.  E.  Whitney, 

Winchester,  Mass. 

512,088 

Jan.  2, 

1894. 

G.  W.  Baker, 

Wilmington,  Del. 

S25.°S2 

Aug.  28, 
Sept.  25, 

1894. 

E.  T.  Marble, 

Worcester,  Mass. 

526,387 

1894. 

W.  Evans, 

Philadelphia,  Pa. 

526,724 

Oct.  2, 

1894. 

C.J.  Mayer, 

Lynn,  Mass. 

528,638 

Nov.  6, 

1894. 

G.  A.  Lawrence, 

Peabody,  Mass. 

535.777 

Mar.  12, 

1895. 

J.  Vaughn, 

Salem,  Mass. 

537.254 

April  9, 

1895. 

tt 

"  " 

539.104 

May  14, 

1895- 

tt 

tt  tt 

546,868 

Sept.  21, 

1895. 

tt 

tt  a 

538,944 

May  7, 

1895. 

G.  W.  Baker, 

Wilmington,  Del. 

540,337 

June  4, 

1895. 

A.  Seymour-Jones, 

Wrexham,  Eng. 

541,262 

June  18, 

1895. 

J.  Boyle, 

Peabody,  Mass. 

547,984 

Oct.  15, 

1895. 

tt  u 

552,628 

Jan.  7, 

1896. 

A.  E.  Whitney, 

Winchester,  Mass. 

552,791 

Jan.  7, 

1896. 

R.  Steyer, 

Dohna,  Germany. 

556,813 

Mar.  24, 

1896. 

W.  Evans, 

Philadelphia,  Pa. 

569,136 

Oct.  6, 

1896. 

A.  F.  Jones, 

Salem,  Mass. 

570,653 

Nov.  3, 

1896. 

A.  E.  Whitney, 

Winchester,  Mass. 

572,532 

Dec.  8, 

1896. 

W.  Evans, 

Philadelphia,  Pa. 

572,533 

578,309 

Mar.  9, 

1897. 

G.  W.  Baker, 

Wilmington,  Del. 

583,995 

June  8, 

1897. 

J.  Hall, 

Leeds,  Eng. 

587.7^ 

Aug.  10, 

1897. 

W.  Evans, 

Philadelphia,  Pa. 

A  copy  of  any  one  of  these  patents  can  be  obtained  by  sending  to 
the  Commissioner  of  Patents,  Washington,  D.  C,  one  coupon  order 
properly  filled  out.  These  coupons  cost  10  cents  each,  in  large  or 
small  quantities. 


INDEX. 


A8' 


1ATING,  153 
Acacia  Arabica  bark,  401 
Acetic  acid,  plumping  by  means  of, 
177.  17S 

and  lactic  acids,  mixture  of,  for 
bating  purposes,  156,  157 
Acid  liquors,  substitution  of,  for  lime, 
90 

Acids,  swelling  effect  of,  upon  the 
skin  fibres,  28 
use  of,  as  bates,  164 

for  toning  down,  539 
Ackerman    &    Brummel's   cut  sole 

factory,  388,  389 
Aesculotannic  acid,  45 
Albumin,  patent,  613 
Alder  bark,  46 

Alizarine  colors,  fixing  of,  on  chrome- 
tanned  leather,  558 
list  of,  566,  567 
dyes,  323 

dyeing  leather  with,  324,  325 
red  on  leather,  556 
Alligator  leather,  466-469 

skin,  japaned  leather  in  imita- 
tion of,  453,  454 
skins,  trade  in,  467,  168 

treatment  of,  468,  469 
Alum,  283,  2*4 

concentrated,  283 
use  of,  as  a  bate,  164 
Alumina,  sulphate  of,  561 
Aluminium  acetate,  284,  285 

hypochlorite,  bleaching  with,  536 
sulphate,  282,  283 

containing    free  sulphuric 
acid,    preparation   of,  for 
tanning  purposes,  283 
detection  of  free  sulphuric 

acid  in,  283 
neutral,  preparation  of,  282 
American  degras  from  wool  waste, 
631 ,  632 
hemlock  extract,  .">4 
hyposulphite  of  soda,  287 
Oak  Leather  Co.,  lay-away  vats 
of  the,  383 
leaching  sys- 
tem in  use 
by  the,  58 

(  655  ) 


American    process    of  oil-dressing 
skins,  232.  233 
sumach,  32 

Tool  &  Machine  Co.,  belt  knife 
leather  splitting  machine  man- 
ufactured by  the,  194-198 
Ammonia  alum,  283 

carbonate,  use  of,  as  a  bate,  164 
muriate  of,  use  of,  as  a  bate,  164 
Anderson,  Wm.,  on  depilating  with 

charcoal,  114 
Angora  goat,  intense  black  for,  498 
Aniline  colors,  adaptability   of,  for 
leather  dyeing,  553 
application  of,  554 
dyeing  power  of,  603 
list  of,  566,  567 
most  important,  583 
practical  dveing  with,564- 
566 

samples  of  leather  dyed 

with,  564-566 
solutions  of,  554 
Animal  skin,  21-28 

structure  of  the,  21 
Anthrax,  629,  630 

Argentine  Republic,  exports  of  que- 
bracho from,  40 
forests  of  quebracho 
trees  in,  40,  41 
Arsenic  and  lime,  active  depilatory 
agent  of  the  mix- 
ture of,  108,  109 
explauation    of  the 
depilatory  power  of 
the  mixture  of,  109 
-lime  paste,  preparation  of,  103 
limes,  335 

red,  part  played  by,  in  the  mix- 
ture of  it  with  lime,  118.  119 
proximate  analysis  of,  118 
results  obtained  by,  111 
use  of,  in  liming,  93 
Artificial  fur,  beaver  and  nutria,  im- 
provements relating  to  the  manu- 
facture of,  500 
Ash  gray,  light,  on  glac£  leather,  607 
Atmospheric  pumps,  13,  14 
Australia,  tanned  sheep-skins  from, 
571 


656 


INDEX. 


Austria,  Russia  leather  manufactured 
in,  47* 

Avellis,  E.,  and  Koster,  E.,  patent  of, 
for  preparing  chrome-tanned 
leathers  for  dyeing,  322 

Avens  root,  47 

BABUL  bark,  401 
Rack  boarding,  373 
Bacteria  pilline,  120 
Bag,  case,  welt,  pocket  book  and  strap 
leather,  and  flexible  splits,  to 
dress,  037,  608 
leather,  414 
Bank  oil,  tanning  principle  of,  L'.'U 

straits  or  menhaden  oil,  228,  229 
Barberry  yellow  on  leather,  557 
Barium  chromate,  286 

sulphide,  depilating  with,  1 14-1 1G 
Bark  business,  fads  in  the,  G4 
conveyer,  68-71 

cutter,  automatic  knife  grinder 
for,  68 

made  by  the  Vaughn  Ma- 
chine Co.,  H6.  G7 
grinding  of,  59,  60 
loss  in  tanning  substance  of,  in 

layaways,  57 
mills,  63-68 

various  constructions  of,  tili 
shaving  of,  181 
Barkometer,  the,  62 
Bartenbach  and  Richter's  quick  tan- 
ning process   for  lace  and  whip 
leather,  546.  547 
Bases,  most  important,  554 
Bassett  belt  knife  splitting  machine, 
202.  203 

Batchelder's  leather  blacking,  color- 
ing and  dressing  machine,  257-262 
Bate,  bran,  155 
coal  tar,  15G 
for  goat  skins,  377,  378 

hides  for  upper  leather,  140 
sole  leather,  160,  161 
liquor,  England  wheels  for  agi- 
tating, 1G6 
manure,  danger  of,  154 
Bates,  substitutes  for,  155 

various,  1G4 
Bath,  definition  of  a,  339 

green,  GIG 
Bating,  88.  153-166 

and  washing,  vats  and  wheels  for, 
165 

compounds,  509 

economies  and  improvements  in, 

93 


Bating,  method  of,  157 

present  method  of,  objections  to, 
1G4 

purpose  of,  !'4 
usual  process  of,  164-166 
Beam  and  stand,  German  form  of,  130 
-face,  glass,  301 

house,  greatest  risk  in  the,  153 

interior  view  of  the,  130 
used  in  currying  ^hops,  250 
Beech  bark,  46 

Beecher  system  of  grinding  bark,  G4 
Beggs  &  Cobb,  system  of  leaching 

hemlock  bark  used  by,  58 
Belt  knife  splitting  machine,  188, 194— 
198 

improvement 
on  grinder 
rigging  for, 
201,  202 
machines,  Robert- 
son's grinding 
adjustment  for, 
203-207 

leather,  machine,  greased  with 
tallow,  405.  40G 
wet  stretching  machine  for, 
409-41 1 
straps,  leather  for,  415 
Belts,  engine,  currving  strap  butts 

for,  407,  408 
Belting  and  harness  leather,  300-411 
for  lighter  purposes,  391,  392 
leather,  hides  used  for,  390 

to  remove  grease  from,  408, 
409 

Bichrome,  330 
Bichromate,  330 

Bichromates,  first  use  of,  for  tanning, 

289 

Bicycle  seats,  leather  for,  414 
Binders,  skivers  and  lining,  512.  513 
Birch  oil  and  leather,  486,  487 
manufacture  of,  484-4*0 
Payen's  apparatus  for  distill- 
ing, 480 
products  of  the  distillation  of. 
486 

Russian  method  of  distilling, 
486.  487 
preparing, 
478,  479 

tar,  487 

and  pine  tar,  differentiation  of, 

488 
oil,  487 
Black  buffings,  plain,  449 

colored  Russia  leather,  484 


INDEX. 


657 


Black  deep  nigrosin,  012 
dyeing  leather,  609,  till) 
enameled  top  leather,  444-447 
intense    dull,    on  bark-tanned 

sheep-skins,  525 
leather,  to  put  a  gloss  on,  505, 

506 

"Norris,"  374 

on  cordovan  leather,  581 

genuine  Russia  leather,  580 

glove  skins,  503,  504 

morocco  leather,  581 

rabbit  skins,  616 

tawed  leather,  582 
spots,  121 

varnish,  preparation  of,  148 
Blacking  brushes,  256 
for  splits,  427 

grain  and  split  leather,  424 
leather,  256-262 
Bleaching  chamber,  533,  534 
chamois  leather,  536 
heavy  leather,  537,  538 
leather,  532-538 

bluing  white  leather,  bleach- 
ing skins  with  the  hair  on, 
532-541 

skins  with  the  hair  on,  540,  541 
with  aluminium  hypochlorite,  536 
hydrogen  peroxide,  535 
magnesium  hypochlorite, 
536 

potassium  permanganate, 
536 

sodium  peroxide,  535 
solution  of  sulphurous  acid, 

534,  535 
sulphurous  acid,  532-534 
Bleeding  or  smutting  off  of  colors, 
563,  564 

Blended  colors  upon  glace"  leather, 

directions  for,  0O4-00N 
Blue-black  liquor  for  finishing,  432 
nigrosin  color,  til  2 
tinge  with  ursol  colors,  498, 
499 

-bluish  on  sheep  skins,  522 
on  morocco  leather,  581 

tawed  leather,  582 
-reddish  on  sheep-skins,  522 

Bluing  white  leather,  536,  537 

Blumenthal,  F.  &  Co.,  plans  of  the 
kid  factory  of,  361-363 

Board,  dyeing  upon  the,  601-603 

Bolton  planimeter,  281 

Bony  fish,  228 

Book  bindings,  leather  for,  414,  415 
Boracic  acid,  use  of,  for  bating,  158 
42 


Borax,  242,  622-628 
•  for  bating,  158 

preserving  hides,  381,  023 
purifying  water,  10,  11 
softening  water,  83,  594,  622. 
623 

in  quick  tanning,  52 
Bordier,  patent  obtained  by,  for  tan- 
ning with  ferric  sulphate,  287 
Borol,  157 

Botchford,  H.  J.,  distillation  of  sour 

liquors  proposed  by,  174,  175 
Bowers  rocker-motion  leather  finish- 
ing machine,  263-265 
Boyden,  Seth,  invention  of  a  splitting 

machine  by,  186 
Bran  bate,  155 

drench,  336 
Brazil,  alligator  skins  from,  467 
Breaking,    fleshing,    unhairing  and 

slating  machine,  331 ,  333 
Brown,  chestnut,  on  leather,  556 
chocolate,  on  leather,  556 
colors  for,  572,  573 
cutch,  011  leather,  556 
dark,  bister,  on   glace  leather, 
605 

on  leather,  555,  550 
glace  leather,  006 
light,  on  leather,  556 
olive,  on  leather,  556 
on  morocco  leather,  581 

tawed  leather,  582 
pure  Havana,  on  glace  leather, 
605 

Sienna,  on  glace"  leather,  605 
wood,   to  mahogany    color  on 
glace  leather,  605 
Brownish  red,  on  glace  leather,  005 
Brush,  scouring,  208 
Brushed  kid,  finishing  of,  368 

seasoning  for,  368 
Brushes,  blacking,  256 
Bublah,  33 

Buenos  Ayres,  process  for  using  pure 
quebracho  wood  for  sole  leather  in, 
41,  42 

Buff  hides,  419 

Buffed  leather,  432,  433 

Buffing  and  whitening  machine, 
Union,  251-254 

Buffings  for  japanning,  classes  of,  444 
plain  black,  449 

Buggy  tops,  black  enameled  leather 
for,'  444-447 

Bull,  A  ,  patent  for  a  bark  mill  re- 
ceived by,  64 

Bull's  leather,  bleaching  of,  537,  538 


658 


INDEX. 


Burns,  Peter  S.,  and  Hull,  Chas.  S., 
invention  of,  156 

CALCIUM  bichromate,  286 
thioarsenite,  depilatory  prop- 
erties of,  119,  120 
Calf,  Dongola,  375,  376 
kid,  best  bate  for,  1-jS 

soaking  of,  84 
leather  dyeing,  569-571 

list  of  dyes  for,  570,  571 
Russia  odor  to,  488 
or  goat  skins,  tanning  of,  by  the 

chrome  process,  304-306 
Russia,  470-474 

coloring  of,  473,  474 
waxed,  quality  of  the  water  in 
the  manufacture  of,  18 
temperature  of  the  water  in 
the  manufacture  of,  15 
Calfskin,  reduction  of,  161 
Calfskins,  chrome-tanned,  correct  ox- 
blood  shade  on,  directions  for, 
573,  574 

combination  tan  or  straight  gam- 
bier  tanned,  formula  for  cor- 
rect ox-blood  shade  on,  567. 568 
dyeing  of,  for  shoe  work,  572,  573 
French  process  of  unhairiug  and 

finishing,  133-135 
in  the  hair,  tanning  of,  491,  492 
mixed  depilatory  for,  98 
paste  for,  427 

tanned,  preparation  of,  for  dye- 
ing, 571 ,  572 

treatment  of,  in  the  limes,  90 
Canaigre,  35,  36 
Cape  sheep,  512 
Caracal,  373 

Carbolic  acid,  use  of,  as  a  bate,  164 
Carbonic  acid  in  water,  recognition 
of,  5 

Card  leather,  splitting  of,  416 
Carriages,  large  hides  and  sides  of 
patent  and  enameled  leather  for, 

392 

Carriage  tops,  black  enameled  leather 
for,  444-447 
hides  for,  436 
Case,  welt,  strap,  pocket  book  and 
bag  leather,  and  flexible  splits,  to 
dress,  637,  638 
Castile  soap,  555 
Catechu,  29,  30 

Cavalin,  first  use  of  bichromates  for 

tanning  by,  289 
Cawnpur  hides,  results  of  tests  of, 
404,  405 


Cawnpur,  India,  system  of  tannage 

used  in  the  factory  at,  401-403 
Chamois  leather,  bleaching  of,  536 
color  of,  532 

mixtures  for,  581 
imitatiou,  510,  511 
Charcoal,  depilating  with,  113,  114 
Chebog,  228 

Chemistry  in  tanning,  154 
Chestnut  brown  on  leather,  556 

oak  bark   liquor,  tanning  sub- 
stance contained  in,  385 
tree,  manufacture  of  tanning 

extract  from  the,  74-76 
wood,  45 
tree,  manufacture  of  tanning  ex- 
tract from  the,  74-76 
Chicago,  sheep  received  in,  507 
Chinese  gall  nuts,  31 
Chloride  of  potash,  355 
Chlorine  combinations  in  water,  de- 
termination of,  4 
Chocolate  brown  on  leather,  556 
Chromates,  neutral,  286 

quick  tanning  with,  Heinzerling's 
process  for,  293-296 
Chrome  bath,  reactions  occurring  in 
the  preparation  of  the, 
352 

Schultz's  directions  for  the 
preparation  of  the,  351 
goods,  solution  to  prevent  com- 
plete drying  out  of,  356 
introduction  of,  326 
leather,  characteristics  of,  319-321 
currying  of,  321 
fat  liquor  for,  321 
leathers,  dyeing  of,  323-325 
or  mineral  tannage,  289-304 
process,    tanning  calf    or  goat 
skins  by  the,  304- 
306 

sheep-skins  by  the, 
306 

tannage,  central  idea  of  methods 
of,  314 

competition  of,  with  bark, 302 
increase  in,  301 
kangaroo,  finishing  of,  425 
some  patents  for,  306-308 
two-bath  method,  tan  vat 
used  in  the,  343 
-tanned   calf-skins,   correct  ox- 
blood  shade  on,  directions 
for,  573,  574 
horse  hide  butts,  wax  finish 

on,  464 
kid,  qualities  of,  326 


INDEX. 


659 


Chrome-tanned  leather,  chromol  fat 
liquors  for,  244 
fixing  of  alizarine 

colors  on,  558 
method  of  color- 
ing, (517,  618 
qualities  of,  301, 

802,  328 
Wm  M.  Norrison, 
328-330 
leathers,  preparation  of,  for 
dyeing,  822 
tanning  and  German  tanners,  307 

methods  now  in  use,  297 
upper  leather,  301 
yellow  on  leather,  557 
Chromic  acid,  deterioration  of  leather 
made  by  the  use  of,  315 
alum,  314 

oxide,  properties  of,  313 
Chromium  alum,  283,  2S4,  286 

preparation  of  the  salt  of,  used 
in  the  Dennis  process,  315,  316 
salts,  285,  286 
sulphate,  286 
Chromol  fat  liquor  for  chrome-tanned 

leather,  244 
Claret  or  maroon  on  sheep-skins,  524 
Clark's  process  of  determining  the 

hardness  of  water,  5-9 
Coal  tar  bate,  156 
Cochineal  on  sheep-skins,  523 
Cod  fishery,  chief  seat  of,  224 
oil,  223-225 

adulterations  of,  225 
classification  of,  224 
manufacture  of,  224 
properties  of,  224 
substitutes  for,  225 
tanning  principle  of,  234,  235 
value  of,  as  a  leather  lubricant, 
235 

Cold  sweat  process,  121 

tan  process  for  fur  skins,  494 
Color,  depth  of  a,  dependent  on  the 
quantity  of  mordant,  575 
facilitating  evenness  of,  562 
imparting  a  light,  to  leather,  538- 
540 

mixtures,  580-584 

production  of  a  definite  tone  of, 

575-577 
scale,  use  of  a,  577,  578 
uniform,  hints  to  obtain  a,  553 
tanners'  preparation  for  ob 
tabling  a,  562,  563 
Coloring     chrome-tanned  leather, 
method  of,  617,  618 


Coloring  kid,  374,  375 

matter,  fixation  of,  by  a  mordant, 

574,  575 
morocco,  374,  375 
Wm.  M.  Norris  on,  374,  375 
Colors,  aniline,  dyeing  power  of,  603 
list  of,  566,  567 
practical  dyeing  with,  564- 
566 

samples  of  leather  dyed 
with,  564-566 
alizarine,  list  of,  566,  567 
bleeding  of,  563,  564 
blended,  584 

upon  glacd  leather,  direc- 
tions for,  604-608 
broken,  toning  fluids  for,  607, 
608 

for  brown,  572,  573 
Russia  calf,  474 
mixed,  608,  609 
smutting  off  of,  563,  564 
waterproof,  560,  561 
Combination  tan  or  straight  gambier 
tanned  calf-skins,  formula  for  cor- 
rect ox-blood  shade  on,  567,  568 
Common  salt,  288,  289 
Compigne,  Dr.,  analysis  of  water  from 

Ganges  Canal  by,  401 
Compo,  463 

Connective  tissue  substance,  formula 
of,  28 
preparation  of, 
27 

properties  of, 
27 

Coombs  pendulum  jack,  271,  272 
Creme  of  logwood,  559,  560 
Crimping  splits,  finishing  of,  425.  426 
Copper,  sulphate  of,  561 
Cordovan,  462-461 

leather,  color  mixtures  for,  581 

sorting  of,  for  dyeing,  585 
Corii'n,  22 

formula  of,  27 

preparation  of,  25 

properties  of,  26 
Corium,  the,  21 ,  22 
Cottle  &  Son,  system  of  leaching 

hemlock  bark  used  by,  58 
Counter-fleshing,  138 
Counters,  389 

Coupe's  stretching  machine,  547-549 
Cow  hides,  soaking  of,  78 
Curriers'  knives,  250,  251 

oils  and  grease,  221-228 

skirting,  395 
Currying  chrome  leather,  321 


66o 


INDEX. 


Currying  harness  leather,  392-395 
Indian  harness  leather,  403,  404 
shops,  beam  used  in,  250 
location  of,  1 
modern,  fitting  up  of,  530 
strap  butts  for  mill  bands  and 
engine  belts,  407,  408 
Cut  sole  factory,  Ackerman  &  Brum- 
mel's,  388,  389 
soles,  387-389 

oak-tanned   sole  leather,  un- 
scoured  and  scoured  leather, 
379-389 
Cutch  brown  on  leather,  556 

DAGGEAT,  479 
Danish  leather,  412,  413 
D'Arcet,  tanning  with  ferric  salts  re- 
commended by,  2S7 
Dark  bister  brown  on  glace  leather, 605 
brown  on  glace  leather,  606 
leather,  555,  556 
gold  ochre  to  umber  on  glace 

leather,  605 
green  on  leather,  557 
pigeon  gray  on  glace  leather,  606 
Daub,  application  of,  446 
for  regalia  leather,  450 
preparation  of,  444,  445 
Deep  black  nigrosin  color,  612 
Deer-skins,  furs  and  peltries,  tanning 

of,  493,  494 
Degras,  226,  230-235,  435,  630,  631 
American  from  wool  waste,  631, 
632 

artificial,  238.  239 
French,  227 

early  use  of,  231 
production  of,  232 
mixture  of,  230 
per  cent  of  water  in,  632,  633 
preparation  of,  230 
Vickers',  231 
Degreasing  liquid,  496 
Deliming,  chemical,  335 
Denmark,  origin  of  the  manufacture 

of  horse  leather  in,  461 
Dennis  Chrome  Tannage  Co.,  direc- 
tions by  the,  for 
tanning  sheep- 
skins, 306 
directions    by  the, 
for  using  tanolin 
on   calf  or  goat- 
skins, 304-306 
new  form  of  sodium 
sulphide  intro- 
duced by  the,  99 


Dennis  method  of  tanning,  298-300 
one-bath  process,  297 

advantages  of,  307 
process  of  tanning  leather,313-319 
tanning  liquor,  308-313 
Depilating  by  sweating,  120,  121 
with  charcoal,  113.  114 

sodium  sulphide,  97-113 
sulphide  of  barium,  114-116 
Depilation,  methods  for  accomplish- 
ing, 86 
or  unhairing,  86-129 
Depilatories,  alkaline,  necessity  of 
the   removal    of,  from  hides 
and  skins,  155 
chemistry  of,  116-120 
Depilatory,  definition  of  a,  86 
Dimitry's  method  of  preparing  water- 
proof colors,  560,  561 
Dipping  apparatus,  599,  600 

process  of  dyeing,  598-600 
Dizer,  M.  C,  &  Co.,  experiments  in 

quick  tannage  by,  527 
Dog-pure,  94 

preparation  of,  163 
Dongola,  blacking  of,  424 
calf,  375,  376 

old  process  of  converting  goat- 
skins into,  376-378 
stuffing  for,  424 
Dow  &  Co.,  system  of  leaching  hem- 
lock bark  used  by,  58 
Drenching,  153 

Dressing  sheep-skin  fleshers  for  glove 

bindings,  513,  518,  519 
Drying  loft  for  sole  leather,  tempera- 
ture of,  385 
in  a  morocco  factory,  364. 
365,  369,  370 
sheep-skin  tannery, 
513,  516 

oven  in  a  patent  leather  factory, 
447 

yard  of  an  upper  leather  tannery, 
422,  423 
Drum,  heating  the,  216.  217 

revolving,  for  handling,  172 
stuffing,  216-21 S 

Freeman's,  221 
tannage,  399,  400 
treating  skins  in  a,  337 
Drums,  tramping,  improvement  in, 
220,  221 

Dung-bating,  theory  of,  163,  164 
Durio,  F.,  process  of  quick  tannage, 
527 

Duval-Duval's  method  of  distilling 
birch  oil,  485 


INDEX. 


Dye  bath,  dilution  of  the,  577 

preparaiion  of  the,  574-578 
-stuffs,  crankisms  of,  553 
selection  of,  583 
ready-made,  working  with,  578 
Dyeing  and  tanning  furs  and  hair 
skins,  491-500 
alizarine  red,  556 
Angora  goat,  498 
barberry  yellow,  557 
bark-tanned  sheep-skins  intense 

dull  black,  525 
board,  the,  601 
calf  leather,  569-571 

-skins  for  shoe  work,  572, 
573 

chestnut  brown,  556 
chocolate  brown,  556 
chrome  leathers,  323-325 

yellow,  557 
Continental  method  of,  558 
cutch  brown,  556 
dark  brown,  555,  556 

green,  557 
dipping  apparatus  for,  599,  600 

process  of,  598-600 
English  method  of,  558 
fluids,  arrangement  of  the,  601 
fur  skins,  494-511(1 
glace  leather,  598 
goat-skins,  497 

imitation  nutria  in  clipped  rabbit, 
498 

seal  skin  in  clipped  musk- 
ox,  498 
leather,  553-616 
black,  609.  610 
for  shoes,  571-573 
methods  of,  used  in  Germany, 

574-616 
with  the  alizarines,  324,  325 
lemon  yellow,  557 
light  brown,  556 

olive  green,  557 
long-haired  musk-ox,  498 
mode  of,  557 

most  important  bases  and  salts 

used  in,  554,  555 
one-tray  process  of,  558 
olive  brown,  556 
operation  of,  691-603 
orange,  557 
ordinary  red,  557 
paddle  method  of,  558 
picric  green,  557 
practical,  appliances  required  for, 

499,  500 
precautions  in,  560 


Dyeing,  preparation  of  chrome-tanned 
leathers  for,  322 
leather  for,  584 
tanned  calf- skins 
for,  571,  572 

rabbit  skins,  497 

black,  616 

red,  556 

russet  leather,  417 
Russia  leather  red,  481 
scarlet,  556,  557 
sheep-skins,  522-525 
sorting  leather  for,  585,  586 
table,  the,  601 
tawed  leather,  598 
Thibet,  497 

two-tray  process  of,  558 
upon  the  board,  601-603 
utensils  required  for,  601 
various  methods  of,  557,  558 
washing  the  skins  for,  586-588 
wild  goat,  497,  498 
with    logwood    and  potassium 
chromate,  610,  611 
mineral  colors,  608,  609 
tannin  and  iron  salts,  610 
logwood,  611 
Dyes  and  toning  fluids,  603,  604 
for  calf  leather,  list  of,  570,  571 
colors  of  a  pure  tone,  604 
glace  leather,  604 
wood,  advantage  of,  556 

EAST  Indian  kino,  29 
Eitner,  Prof.,  method  for  employ- 
ing quebracho  with 
oak  bark  for  sole 
leather  recommend- 
ed by,  42,  43 
on  the  uses  of  que- 
bracho, 38,  39 
Egg,  yolk  of,  preservation  of,  597 
Electric  and  other  rapid  tannage  sys- 
tems, 526-531 
transmission  of  power,  636,  637 
Elm  bark,  45 

Enamel,  horse  hides  for,  464,  465 
Enameled  leather,  patent  leather, 
furniture  or  up- 
holstering leather, 
regalia  leather,  436- 
460 

stuck  together,  a  good 

way  to  open,  451 
stuffing  for,  440,  441 
or  japanned  leather,  preparing 
the  cut  surface  of  split  leather 
for  manufacturing,  452,  453 


662 


INDEX. 


Enameled  varnish,  446 
Engine  belts,  currying  strap  butts  for, 
407,  408 

England,  L.  C,  apparatus  invented 

by,  168-170 
England  wheel,  bating  in  the,  420 
wheels  for  agitating  bate  liquor, 
166 

English  crown  leather,  grain  of,  418, 
419 

sod  oil,  226,  227 
Euos,  John  A.,  attachment  to  the 
Union  splitting  machine,  patented 
by,  188,  190-192 
Epidermis,  composition  of  the,  21 

nature  of,  112 
European  galls,  30,  31 

FAHR,  George,  discovery  of  the 
tanning  properties  of  quebracho 
by,  37 

Fat   liquor,    chrotnol,    for  chrome- 
tanned  leather,  244 
for  chrome  leather,  321 
formula   for  making,  with 

Palermo  fig  soap,  243 
use  of  degras  as,  231 
liquoring  with  Palermo  fig  soap, 

242,  243 
liquors,  243,  244 
Fats,  most  common  and  abundant, 
223 

properties  of,  222 
Fawn,    production    of  modification 

with,  575 
Ferric  salts,  287,  288 

Knapp's  method  of  prepar- 
ing, 292 
patent  for  tanning  with, 
290-292 

sulphate,  basic,  preparation  of,290 
preparation  of,  287,  288 
Ferrocyanide  of  potassium,  561 
Fiebing,  Prof.,  on  the  use  of  sodium 

sulphide  for  depilating,  97,  98 
"  Fine  hair,"  109 

hairing,  best-time  for,  158 
Finish,  bright,  for  glove  grain,  430, 
431 

coat  for  flesh  splits,  430 
for  imitation  goat  grain,  431 
kangaroo,  431 
pebble  grain,  431 
satin  oil  leather,  431 
gum  tragacanth,  426,  427 
Finishing  and    pebbling  machine, 
Knox  improved  inclined  bed, 
268-271 


Finishing  blue  black  liquor  for,  432 
furniture  leather,  449 
machine,  Bowers  rocker  motion, 
263-265 
Martin's    improved,  267, 
268 

polishing  or  glassing,  pebbling, 
rolling,  etc.,  machines  for,  263- 
272 

room,  the,  450 

in  a  sheep-skin  tannery,  513, 
517 
skirting,  395 
upholstering  leather,  449 
varnish     for    smooth  finished 
patent  leather,  449 
Fir  bark,  34 

Fischerstroem's  method  of  distilling 

birch  oil,  485 
Fish  oil,  conversion  of,  to  sod  oil,  by 
oxidation,  234 
value  of,  as  a  leather  lubricant, 
235 

Flanders,  Jos.  F.,  and  Marden,  Jere 
M.,  invention  of  the  belt  splitting 
machine  by,  188 
Flesh  splits.  429-432 

finish  coat  for,  430 
stuffing  for,  429 
Flesher,  saw-toothed,  136 
Fleshers,  spring,  136 
Fleshing  and  unhairing  by  hand  and 
machinery, 
130-152 
by  machinery, 

140-152 
machines, 
practical 
success  of, 
151 

by  the  hand  method,  135-138 
green,  379 

how  long  should  the  hides  soak 
after,  and  what  indicates  their 
readiness  for  scouring,  139, 140 
knife,  135,  136 
Flexible  splits,  433-435 

to  dress,  637,  638 
Float  for  whole  hides,  184 
Foederer,  R.  H.,  first  production  of 
commercial    leather    tanned  by 
Schultz's  process  by,  298 
Foley,  process  for  treating  hides  and 
skins  previous  to  tanning  invented 
by,  114-116 
Forbes,  Prof.,  on  the  value  of  canaigre 

tanning  materials,  36 
Forster's  sandstone  filter,  594,  595 


INDEX. 


663 


Foss,  C,  earliest  patent  for  a  bark 

mill  awarded  to,  63,  G4 
Frame  for  stretching  leather,  441-443 
Frames  for  japanning  side  leather, 
444 
hide,  444 
split,  444 

France,   process  of  unhairing  and 
finishing  calf  skins  in,  133-135 

Freeman  &  Co.,  improved  iron  glass- 
ing jack  made 
by,  266 
straight  bed  roll- 
ing  or  peb- 
bling jack 
made  by,  266, 
267 

stoning  jack  made  by, 

1S5,  415 
stuffing  drum,  221 
Union  whitening  and 
buffing  machine 
made  by,  251-254 
French  degras,  227 

early  use  of,  231 
production  of,  232 
kid,  imitation,  finishing  of,  366- 
368 

selection  of  skins  for, 
368 

method  for  tanning  oil-dressed 

leather,  232 
moellon  oil,  227 
sumach,  32 
whitening  slicker,  250 
Frieze,  121 

Fur,  artificial,  beaver  and  nutria,  im- 
provements   relating    to  the 
manufacture  of,  500 
skins,  cold  tan  process  for,  494 
mordants  for.  4! Hi 
Furniture  or  upholstering  leather,  fin- 
ishing of,  44il 
leather,  regalia 
leather,  enam- 
eled leather, 
patent  leather, 
436-460 

Furs   and    hair-skins,  tanning  and 
dyeing  of,  491-500 
peltries  and  deer-skins,  tanning 
of,  493,  494 
Fustic,  33,  34 
young, 559 

GALL  nuts,  30.  31 
Galls,  31 
•Gambier,  29 


Ganges  Canal,  analysis  of  water  from 

the,  401 
Geranium  wallachianum,  47 
German  fleshing  knife,  135,  136 

harness  leather,  395-397 
Germany,  methods  of  dyeing  leather 

used  in,  574-616 
Gift,  lu'.i 

Gilbert  Bros.  &  Co.,  tanners'  prepar- 
ation, prepared  by,  562,  563 
Glace  leather,  blended  colors  upon, 
directions  for,  604-608 
dyeing  of.  598 
dyes  for,  604 
nourishment  for,  596 
sorting  of,  for  dyeing,  585 
washing  tawed  skins  for, 
586,  587 

Glassing  jack,  improved  iron,  266 
or  polishing,  finishing,  rolling, 
pebbling,  etc.,  machines  for, 
263-272 

Glazing  and  glassing  of  leather,  012- 
615 

fluid,  preparation  of,  012,  613 
leather,  012.  (113 
machine,  263 
rolls,  615 

Gloss,  to  put  a,  on  black  leather, 
505,  506 

Glossing  and  glazing  of  leather,  612- 
615 

apparatus,  614,  615 
leather,  614,  615 
mass,  614 
Glove  bindings,  dressing  sheep-skin 
fleshers  for,  513,  518,  519 
grain,  blacking  of,  424 

bright  finish  for,  430,  431 

finishing  of,  425 
stuffing  for,  422.  424 
kid,  alum  tawed,  aging  of,  106, 
107 

effect  of  sodium  sulphide  on, 
106 

reasons  why  sodium  sulphide 
should  not  be  used  for  mak- 
ing, 107    1 18 
leather,  tawing,  dyeing  lamb  and 

kid  skins  for,  501-504 
leathers,  inability  to  get  colors 

right  in,  161 
sheep  leather,  natural  tan,  sample 

of,  565 
skins,  black  on,  503,  504 
Glue,  conversion  of  the  connective 

tissue  fibres  into,  23,  24 
Glycerine,  236-240 


664 


INDEX. 


Glycerine  albuminous,  239 

combination  of,  with  tannin,  239 
fixing  of,  in  the  leather,  239 
for  nourishing,  59(i 

softening,  412,  413 
properties  of,  237 
stuffing  with,  239,  240 
use  of,  238 
Goat,  Angora,  intense  black  for,  498 
grain,  imitation,  finish  for,  431 
finishing  of,  42") 
stuffing  for,  424 
India  tanned,  364 
oil,  finishing  of,  373,  374 
or  calf-skins,  tanning  of,  by  the 

chrome  process,  304-306 
pebble-grain,  finishing  of,  373 
-skin,  dyed  sample  of,  565,  506 
India    tanned,    dark  green, 
dyed    sample  of, 
566 

dyed    sample  of, 

565 

-skins,  arsenic  in  liming,  93 
bate  for,  377,  378 
d3*eing  of,  4!i7 

high-limed  bating  of,  157, 158 
imported  from  India,  364 
in   the   hair,  bleaching  of, 

540,  541 
liming  of,  377 
mill  for,  377 

mixed  depilatory  for,  98 
old   process  of  converting, 
into   Dongola    and  other 
fine  leathers,  376-378 
preparing  the,  330-336 
sumac  tannage  of,  378 
tawing  of,  336-343 
straight-grained,  finishing  of,  368- 
373 

graining  of,  371 
seasoning  for,  369 
wild,  dark  brown  for,  497 
gray  brown  for,  497,  498 
Gold  ochre,  dark,  to  umber  on  glace 

leather,  605 
Goodyear  counters^  389 

insoles,  389 
Gorsline's  apparatus   for  handling, 

172,  173 
Grain,  the,  421 

and  split  leather,  418-435 
artificial,  on  hides,  452,  453 
false,  uneven,  prevention  of,  418 
leather,  handling  of  sides  for,  172 
Grainering,  153 
Graining,  166,  380 


Graining  board,  371 

machine,  Towein's,  483 
straight-grained  goat,  371 
Grass  green  on  sheep  skins,  523,  524 
Gravity  system  of  leaching,  49 
Gray  on  tawed  leather,  582 
Grease  and  oils,  curriers',  221-228 
"Ideal,"  228 

removal  of,  from  leather  belting, 

408,  409 
Green  bath,  616 

brown  to  dark  brown  on  glace 

leather,  606 
dark,  on  leather,  557 
fleshing,  379 
galls,  30 

light  olive,  on  leather,  557 
on  morocco  leather,  581 
picric,  on  leather,  557 
on  tawed  leather,  582 
Grinding    adjustment,  Robertson's, 
for  belt  knife  splitting  machines, 
203-207 _ 

Grinder  rigging  for  belt  knife  split- 
ting machines,  improvement  on, 
201,  202 

Groth  system  of  rapid  tannage,  526 
Grouvelle's  process  of  distilling  birch 
oil,  485 

Gum  tragacanth  finish,  426,  427 

HAHN  &  STUMPF,  wax  finish  on 
chrome-tanned  horse-hide  butts 
made  by,  404 
Hair  bulbs,  23 

primitive  manner  of  removing,  89 
roots,  23 
sacs,  23 

Hairskins  and  furs,  tanning  and  dye- 
ing of,  491-500 

Hamburg,  manufacture  of  horse 
leather  in,  462 

Hand  method  staking  machine,  273. 
274 

reel,  the,  168 

stuffing,  215,  216 
Handler  vats,  421 
Handlers,  382 

liquors  going  on  the  hides  in  the, 
383 

Handling,  167-173 

and  plumping,  167-178 
England's  apparatus  for,  168-170 
European  methods  of,  172 
Gorsline's  apparatus  for,  172,  173 
methods  of,  167 
paddle  wheels  for,  170,  171 
revolving  drum  for,  172 


INDEX.  665 


Hardness  of  water,  degrees  of,  9 

determination  of,  5-9 
Harness  and  belting  leather,  390-41] 
large  hides  and  sides  of  patent 
and  enameled  leather  for,  392 
leather,  brown,  393,  394 
currying  of,  392-395 
drum  tannage  for,  399,  400 
Gentian,  395-397 
hides  used  for,  390 
Indian,  4(10-4(15 

currying  of,  403,  404 
tanning  process  for,  402, 
403 

tests  of,  404,  405 
quick  tanning   process  for, 
392 

requisite  qualities  of,  390 
Hart,  R.,  process  of,  for  dressing 

sheep-skin  fleshers,  513,  518,  519 
Hauff,  P.,  patent  of,  157 
Havana  brown,  pure,  on  glace  leather, 

605 

Heading,  181 

Heinzerling's  process  for  quick  tan- 
ning with  chromates,  293-296 
Hemlock  bark,  114 

system  of  leaching,  58 
extract,  preparation  of,  76 
Hestahl's  process  for  dressing  sheep- 
skins, 520,  521 
Hibbard's  method  for  preparing  and 

tanning  sheep-skins,  520 
Hide,  cleansing  the,  with  borax,  52 
constitution  of,  112 
frames,  444 
grain  of  the,  112 

green,  object  of  applying  a  mel- 
low liquor  to  a,  57,  58 
mills,  construction  of,  84 
practice  of  reducing  the,  161 
substance,  necessity  of  removing 

a  certain  amount  of,  105 
thoroughly  tanned,  test  for  a,  396 
Hides  and  skins,  preparation  of,  for 
soaking,  79-81 
working  out  and  un- 
hairing  all  kinds  of, 
without  limes,  bate, 
drench  or  beaming, 
116 

artificial  grain  on,  452,  453 
borax  for  preserving,  381 
buff,  419 

buffing  of,  for  japanning  or  enam- 
eling, 452 
dried,  soaking  of,  79 
dry,  softening  of,  84 


Hides,  dry,  softening  of,    for  sole 
leather,  82 
final  soaking  of,  before  placing 

in  the  ooze,  166 
for  belting  leather,  390 
enameled  leather,  436 

or  patent  leather,  split- 


tanning  of, 
439,  440 
furniture  leather,  436 
grain  and  split  leathers,  419 
harness  leather,  390 
Indian  harness  leather,  4((1 
lace  leathers,  542 
limed  stock,  preparation  of, 
89 

patent  leather,  436 
regalia  leather,  450 
upholstering  leather,  436 
upper  leather,  bate  for,  140 
vache  leather,  399 
fresh,  sweating  of,  128,  129 
green,  for  upper  leather,  lime  for, 
399 

soaking  of,  79 
hand-buffed,  grades  of,  443 
heavy,  final  step  in  the  process 

of  tanning,  181 
horse,  treatment  of,  461.  462 
indications  of  the  readiness  of, 

for  scouring,  139,  140 
ledger  account  of,  382 
light,  consequence  of  the  use  of 
too  concentrated  solutions 
of  tannin  for,  390 
soaking  of,  84 
machine  buffed,  grades  of,  444 
mechanical  devices  for  stretch- 
ing, 543,  544 
native  slaughtered,  soaking  of,  79 
or  skins,  art  of  tawing,  6lN-i;22 

building    for  sweating, 
121-124 

percentage  of  rough  leather  ob- 
tained from,  386 
plumping  of,  3 

Russian  method  of  freeing  from 

lime,  47s 
soaking  of,  after  fleshing  by  the 
hand  method,  138, 
139 

in  a  steeping  cistern 
after  fleshing,  139 
splitting  of,  for  grain  and  split 

leather,  421 
South  American,  379 


666 


INDEX. 


Hides,  sweating  of,  care  to  be  observed 

in,  124-127 
swelling    influence    of  natural 

waters  upon,  26 
swelling  of,  3 

temperature  of  the  water  for  pre- 
paring the,  4 
Texas,  379 

unhairing    of,    bv    the  hand 

method,  130-135 
washing  of,  for  enameled  or  pat- 
ent leather,  437 
whole,  float  for,  184 

jack  for  raising  the,  up  in  the 

lay  away  vats,  183 
splitting  of,  188 
Hirschsohn's  process  of  differentia- 
tion of  birch  tar  and  pine  tar,  488 
Hog  and  seal,  imitation,  427,  428 
Holbrook  system  of  leaching,  51 
Horse-chestnut  bark,  45.  46 
extract,  4<> 
hide  butts,  chrome-tanned,  wax 

finish  on,  4C>4 
hides  for  enamel,  4t>4,  465 
memel,  465 
plain  enamel,  465 
shoe  purposes,  462-464 
treatment  of,  461,  462 
leather,  461-465 
Hydrochloric  acid,  use  of,  as  a  bate, 
164 

Hydrogen  peroxide,  bleaching  with, 

535 

Hyposulphite  of  soda,  287 

action  of  muriatic 
acid  upon,  355 

determination  of 
the  proper 
amount  of  acid 
to  use  in  con- 
nection with, 
354 

and  potassium  bi- 
chromate, de- 
termination of 
the  proper  rela- 
tion between, 
354 

U  TDEAL"  grease,  228 

I    Illinois,  varieties  of  leather  pro- 
duced in,  419 
Imitation  goat,  blacking  of,  424 
grain,  finish  for,  431 
finishing  of,  425 
stuffing  for,  424 
seal  and  hog,  427,  428 


India,  goat  skins  imported  from,  364 
harness  leather,  400-405 

currying  of,  403,  404 
new,  tests  of,  404,  405 
process   of  tanning, 
402,  403 
tanned  goat,  304 

skin,  dark  green,  dyed 

sample  of,  ~><>0 
dyed  sample  of,  565 
Indigo  carmine,  559 

dyeing  power  of,  603 
Ingersoll-Sergeant    Drill    Co.,  the 
Pohle  system  of  raising  water,  in- 
troduced by  the,  16 
Intercellular  substance,  25 
Iron  alum,  283,  284 

gray  on  glace1  leather,  607 

salts  and  tannin,  dyeing  with,  (>10 

soap,  288,  291 

violet  on  glace  leather,  606 
Italian  sumach,  31 
Itch,  95-97 

white,  96 

JACK,  Coombs  pendulum,  271,  272 
for  raising  whole  hides  up  in  the 
lay-away  vats,  183 
glassing,  improved  iron,  266 
stoning,  185,  415 
straight  bed  rolling  or  pebbling, 
266,  267 

Japanned  leather  in  imitation  of  alli- 
gator skin,  453,  454 
renewing   the  surface 
on,  451 

Japanned  or  enameled  leather,  pre- 
paring the  cut  surface  of  split 
leather,  for  manufacturing,  452,  453 

Japanning,  buffings  for,  444 

side  leather,  frames  for,  444 

Jones'  patent  bark  cutter,  66,  67 

Juften  or  Juchten,  475 

Junior's  method  of  manufacturing 
lace  leather,  545,  546 

KANGAROO  chrome-tannage,  fin- 
ishing of,  425 
finish,  431 
stuffing  for,  421 
Kits,  S,,  on  quick  tannage,  527 
Kettles,  steam  jacket,  242 
Kid  and  lamb  skins  for  glove  leather, 
tawing,  dveing  of,  501-504 
brush,  the. '368 
brushed,  finishing  of,  368 

seasoning  for,  368 
chrome-tanned,  qualities  of,  326 


INDEX. 


667 


Kid,  coloring  of,  374,  375 
colors  for,  583 

factory,  F.  Blumenthal  &  Co.'s., 

plans  of  the,  361-363 
imitation   French,  finishing  of, 
366-368 
selection  of  skins 
for,  368 
leather,  bluing  of,  536,  537 
or  morocco  factory,  lime  vats  in 
a,  331,  332 
leathers,  326-378 
tanneries,  breaking,  fleshing,  un- 
hairing  and  slating  machine 
used  in,  331,  333,  334 
tanners  of  Philadelphia,  Penna., 
softening  mill  used  bv,  84,  85 
Kino,  29 

Klipsteiu  &  Co.  on  the  qualities  and 

use  of  quebracho,  39 
Kips^for  upper  leather,  lime  for,  399 
Knapp,    Prof,    experiments  of,  in 
making  leather  without 
tanning  elements,  179- 
181 

experiments  of,  in  tan- 
ning with  ferric  salts, 
287,  288 
improvement  in  tramping 

drums  by,  220,  221 
patent  obtained   by,  for 
tanning  with  ferric  salts, 
290-292 
Knife,  fleshing,  135.  136 

grinder,  automatic,  for  bark  cut- 
ter, 68 
short  hair,  133 
unh  airing,  130 
Knives,  currier's,  250,  251 
Knoppern,  31 

Knox  improved  inclined  bed  leather 
finishing  and  pebbling  machine, 
26S-271 

Koechlin,  H..  and  Knecht,  B..  pro- 
cess by,  of  dyeing  leather  with  the 
alazarines,  324,  325 

LABARRAQUE'S  solution,  prepara- 
tion of,  540 
Lac  brown  on  glace  leather,  006 
Lace  and  whip  leather,  quick  tanning 
process  for,  546.  547 
leather,  golden  color  on,  545 

Junior's  method  of  manu- 
facturing, 545.  546 
Loescher's  method  for  man- 
ufacturing, 547 
leathers,  542-552 


Lactic  acid,  323 

plumping  with,  178 
Lamb  and  kid  skins  for  glove  leather, 
tawing,  dyeing  of,  501-504 
-skins  in  the  hair,  bleaching  of, 
54(1.  541 

Lang  Co.,  Newark,  N.  J.,  Pohle  air 
lift  plant  at  the  works  of  the,  19,  20 
Larch  bark,  34 
Latches,  Indian,  40i' 
Lay -away  vats,  181,383 

jack  for  raising  the  whole 

hides  up  iu  the,  183 
liquors  in  the,  183 
yard,  383 
Layers,  number  of,  181.  182 
Laying  away,  179-1M 
Leach,  bead,  general  rule  for  the,  50 
ideal,  50,  51 

ledger  account  for  each,  60 
limit  to  the  length  of  the  column 

of  bark  in  a,  55 
pumps,  52 
Leaches,  pumping  of,  59 

tail,  temperature  of  the  water  or 

liquor  applied  to  the,  56 
Leaching,  48-62 

barkometer;    bark   mills;  bark 

conveyer;  the  tan  press,  48-73 
cardinal  points  to  be  considered 

in,  48 

check  on  the  efficiency  of,  56,  57 
difficulty  experienced  in,  53 
forced,  systems  of,  48 
gravity  system  of,  49 
Holbrook  system  of,  51 
illustration  of  the  most  common 

way  of,  49 
most  seriously  defective  system 

of,  51 .  52 
point  of  saturation  in,  50 
pumping  in,  54.  55 
regulation  of  the  temperature  iu, 

52,  53 

remedy  for  packing  in,  54 
Leather,  alligator,  466-469 
and  birch  oil,  486,  487 
assorting  of,  for  dyeing,  555 
belting,  to  remove  grease  from, 
408,  409 

black,  to  put  a  gloss  on,  505,  506 
blacking,  coloring  and  dressing 

machine,     Batchelder's,  257- 

262 

bleaching  of,  532-538 
buffed,  432.  433 

chrome  tanned,  method  of  color- 
ing, 617,  618 


668 


INDEX. 


Leather,  Danish,  412,413 

dressing,  bating  of,  in  the  United 
States,  160 

dyeing  of,  553  -616 

enameled,  patent,  furniture  or 
upholstering,  regalia,  436-460 

finishing  machine,  Bowers  rocker- 
motion,  263-265 

frame  for  stretching,  441-443 

German  harness,  395-397 

glazing  and  glossing  of,  612-615 

grain  and  split,  418-435 

hard,  112 

harness  and  belting,  390-411 
heavy,  bleaching  of,  537,  538 

upper,  practice  of  handling, 
184 

splitting  the  sides  in  the 
manufacture  of,  188 
horse,  461-465 

imparting  a  light  color  to,  538- 
540 

list  of  patents  relating  to  the 
manufacture  of,  639-654 

making  of,  without  tanning 
elements,  179-181 

manufactories,  Russia,  locations 
of,  476 

methods  of  dyeing  used  in  Ger- 
many, 574-616 
over-bated,  153 

plauimeter  for  showing  the  area 
of,  281 

preparation  of,  for  dyeing,  584 
raw  products  for,  21 
Russia,  manufacture  of,  475-484 
russet,  414-417 

sample  of,  tanned  with  quebracho 

extract,  39 
scoured,  preparation  of  hides  for, 

386 

sorting  of,  for  dyeing,  585,  586 

splitting  of,  186-207 

hints  for,  193,  194 
practice  of,  188,  189 

spongy, 112 

standard  of  measurement  of,  278 
suppleness  an  indispensable  re- 
quisite for,  87,  88 
tallowed,  currying  of,  406,  407 
underbated,  153 
vache,  preparation  of,  397-399 
varieties  of,  tanned  by  the  Den- 
nis process,  300 
washing  of,  rules  for,  592 
weighted  with  sugar,  testing  of, 
489 

weighting  of,  489,  490 


Leather,  water-proofing,  245-247 
white,  511 

bluing  of,  536.  537 
Leathers,  chrome,  dyeing   of,  323- 

325 

-tanned,  preparation 
of,  for  dyeing,  322 
kid  or  morocco,  326-378 
lace,  542-552 
light,  puring  of,  158,  159 
machines  for  measuring,  277-281 
sheep,  507-525 
Lemon  yellow  on  leather,  557 
on  sheep-skins,  523 
Lifting  pumps,  13,  14 
Light  brown  on  leather,  556 

ochre  yellow  on  glace  leather,  604 
olive  green  on  leather,  557 
Lime,  86-97 

action  of,  94 

air-slaking  of,  87 

effect  of,  when  left  in  leather,  159 

for  vache  leather,  3(19 

tanners'  use,  slaking  of,  87 
inconveniences  in  the  use  of,  87 
in  water,  recognition  of,  5 
necessity  of  the  removal  of,  from 

hides  and  skins,  155 
pit,  old,  well-plunged,  analysis  of 
a  sample  of  liquor  from  an,  116, 
117 

pits,  management  of,  Sit,  90 
preparation  of,  86 
purpose  of  the  use  of,  93.  94 
putrid,  effect  of,  112,  113 
Russian  method  of  freeing  hides 

from,  478 
stones,  87 

substitution  of  acid  liquors  for, 
90 

vat,  new.  preparation  of  a,  91, 
94,  95 

vats,  construction  of,  91 

in  a  kid  or  morocco  factory, 
331,  332 
Limes,  arsenic,  335 
cleaning  of,  420 

effect  of  sodium  sulphide  in  the, 
104 

for  Dongola  calf,  375 
old,  use  of,  92 

treatment  of  calf-skins  in  the,  90 
Liming,    economies    and  improve- 
ments in,  93 
goat  skins,  377 
object  of,  420 

process,  inconveniences  of,  88 
time  employed  for,  92,  93  . 


INDEX. 


669 


Liming,  too  long  continued,  effect  of, 
26 

Lining,  binders  and  skivers,  512,  513 
Linseed,  constituents  of,  454,  455 

driving  off  the  mucilage  from, 

459 
oil,  454-4(50 

boiled,  test  for,  459 

by  extraction,  455 

chemical  changes  induced  in, 

by  exposure  to  the  air,  458 
cold  drawn,  455 
commercial  forms  of,  458 
detection  of  adulterations  of, 
457 

ordinary,  455 
properties  of,  455,  45(5 
raw,  boiling  of,  444,  445 
reasons  for  boiling,  459 
reactions  of,  with  acids,  45(5, 
457 

selection  of,  458 
uses  of,  457,  458 
Liquor,  sour,  plumping  by  means  of, 
173-175 

Liquors,  sour,  distillation  of,  174,  175 
Live-oak  wood,  47 

Loescher's  method  for  manufacturing 

lace  leather,  547 
Logwood,  33 

and  potassium  chromate,  dyeing 
with,  610,  611 
tannin,  dyeing  with,  611 
creme  of,  559,  50(1 
Lombardy  poplar  bark,  45 
Louisiana,  alligator  hunting  in,  466 

MCKAY  counters,  389 
McMillan,  Walter  G.,  on  Indian 
harness  leather,  400-405 
MacBride,    David,    introduction  of 
plumping  by   means   of  sul- 
phuric acid  by,  175 
use  of  hydrochloric  acid  as  a  bate 
by, 164 

Machine  belt  leather  greased  with 

tallow,  405,  406 
Machines   for    measuring  leathers, 
277-281 
rolling,  pebbling,  glass- 
ingorpolishing,  finish- 
ing, etc.,  263-272 
Magnesia  in  water,  recognition  of,  5 
Magnesium  hypochlorite,  bleaching 
with,  536 

Mail  bags,  United  States,  leather  for, 
414 

Maize  yellow  on  glace  leather,  604 


Malabar  kino,  29 
Malpighni's  net,  21 
Manganese  alum,  283,  284 
Manasse's  method  for  tawing  sheep- 
skins, 519 
Manure  bate,  danger  of,  154 
Maroon  or  claret  on  sheep-skins,  524 
Martin's  improved  finishing  machine, 
267,268 
staking  machine,  275,  276 
tan-press,  71-73 
Mason,  Wm.  M.,  building  for  sweat- 
ing hides  or  skins  invented  by,  121— 
124 

Massachusetts,   varieties  of  leather 

produced  in,  419 
Measurement  of  leather,  standard  of, 

278 

Measures  and  weights,  500 
Measuring  leathers,   machines  for, 
277-281 
machine,  Sawyer's,  277-279 
Union,  279-281 
Memel,  horse  hides  for,  465 
Menhaden,  228 
fishery,  228 

oil,  detection  of,  in  cod  oil,  225 

tanning  principle  of,  234 
Straits  or  Bank  oil,  228,  229 
Merritt,  F.  S.,  patent  of,  for  produc- 
ing japanned  leather  in  imitation 
of  alligator  skin,  453,  454 
Mesquite  oak  wood,  47 
Michigan,  varieties  of  leather  pro- 
duced in,  419 
Mill  bands,  currying  strap  butts  for, 
407,  408 
for  goat  skins,  377 
softening,  used  in  Philadelphia, 
Penna.,  84,  85 
Mimosa,  47 
Mimotanuic  acid,  571 
Mineral  acids,  plumping  with,  178 
colors,  dyeing  with,  608,  609 
or  chrome  tannage,  289-304 
tanning,  antiquity  of,  282 

substances,    chrome  or 
mineral  tannage, 
characteristics  of 
c h  r  o m  e-t  autied 
leather,  currying, 
dyeing,  282-325 
principal,  282 
Mixed  color,  608,  609 
Moellon  oil,  French,  227 
Monk's  scouring  machine,  209-212 
Mordant,  depth  of  a  color  dependent 
on  the  quantity  of,  575 


670 


INDEX. 


Mordant,  fixation  of  coloring  matter 
by  a,  574,  575 
for  Russia  leather,  482 
of  tin  salt,  preparation  of  a,  575.576 
Mordants,  561,  562 
definition  of.  554 
for  calf  leather,  570 

fur  skins,  496 
groups  of,  554 
Morocco,  coloring  of,  874,  375 

factory,  drying  loft  in  a,  864,  365, 
369,  370 
finishing  room  in  a,  366,  367 
rolling  and  glazing  room  of 
a,  371,  372 
leather,  color  mixtures  for,  581 

water-proofing  of,  247 
manufacture, revolution  in  the, 326 
or  kid  factory,  lime  vats  in  a, 
331,  332 
leathers,  326-378 
sorting  of,  for  dyeing,  585 
tanners  of  Philadelphia,  Penna., 
softeuiug  mill  used  by,  84,  85 
Moss  bunker,  228 
Muriatic  acid,  353 

action  of,  upon  hyposulphite 
of  soda,  355 
Musk  ox,  clipped,  imitation  of  seal 
skin  in,  dyeing  of,  498 
long-haired,  light  brown  for, 
498 

Myrobalans,  33 

NAPHTHA,  use  of,  as  a  reducing 
agent,  450 
Naphthalene  sulphonic  acid,  156 
Neatsfoot  oil,  228,  229,  280 
Newfoundland  cod  oil,  228 
New  York,  varieties  of  leather  pro- 
duced in,  419 
Zealand,     tanned  sheep-skins 
from,  571 
Nigrosin  color,  blue  black,  612 

deep  black,  612 
"Norris"  black,  374 
Norris,  Wm.  M.,  on  chrome-tanned 
leather,  328- 
330 

coloring,  374, 
375 

Schultz's  pat- 
ents, 346,  347 
patent  of,  for  coloring 
chrome- 
tanned 
leather, 
617,  618 


Norris,  Wm.  M.,  patent  of,  for  tawing 

hides  or 
skins, 
618-622 

Nourishing,  595,  596 
Nutria,  imitation,  in  clipped  rabbit, 
dyeing  of,  49<S 

OAK  bark,  34,  35 
with  quebracho,  method  for 
employing,  42.  43 
tanned  sole  leather,  schedule  of 
the  time  and 
strength  of 
liquor  em- 
ployed in  each 
laver  for,  383, 
384 

un  scoured  and 
scoured  leath- 
er, cut  soles, 
379-389 
Oil,  best,  for  leather,  223 

brown  seal ;  detection  of,  in  cod 
oil,  225 

distinct  classes  of  bodies  em- 
braced in  the  name  of,  222 
dressed  leather,  French  method 

for  tanning,  232 
dressing  skins,  American  process 
of,  232,  233 
European  method 
of,  233 

for  Dongola  calf,  375 

plow  grain,  429 
goat,  finishing  of,  373,  374 
grain,  blacking  of,  424 

finishing  of,  430 
menhaden,  detection  of,  in  cod 

oil,  225 

of  vitriol,  properties  of,  176,  177 

porpoise,  229 

tunny,  22'.) 
Oils  and  grease,  curriers',  221-228 

fixed  or  fatty,  222 

mineral,  222 

detection  of.  in  cod  oil,  225 

testing  of,  240,  241 

volatile  and  essential,  222 
Old  grain,  121 
Olein,  228 
Oleo-stearine,  227 
Olive  brown  on  leather,  556 

on  glace  leather,  606 
Oliver,  C.  P.,  and   Howell,  T.  P., 

frame  for  stretching  leather  in- 
vented by,  441-443 
Orange  on  leather,  557 


INDEX. 


671 


Orange  on  morocco  leather,  581 
Organic  acids,  use  of,  as  a  bate,  1G4 
substances  in  water,  recognition 
of,  5 

Ox-blood  shade,  correct,  on  chr ome- 

tanned 
calf- 
skins, 
direc- 
tions 
for,  573, 
574 
combina- 
tion tan 

or 
straight 
gam  bier 
tanned 
calf- 
skins, 
formula 
for,  567, 
568 

PADDLE  method  of  dyeing,  558 
wheels  for  handling,  170,  171 
Palermo  fig  soap,  formula  for  making 
fat  liquor  with,  243 
stuffing  or  fat-liquor- 
ing with,  242,  243 
Palmetto  root,  41,  4"> 
Palmitin,  223 

Parafnue  oil,  for  rendering  leather 

pliable,  615 
Paraffine  wax,  227.  235,  236 
Paste  for  upper  splits  and  calf-skins, 
427 

wax  stock,  427 
Patcher,  the,  443 

Patent  leather  factory,  drying  oven  in 
a,  447 
tanning    vats  in, 
438 

furniture  or  upholstering 
leather,  regalia  leather, 
enameled  leather,  436- 
460 

preserving  the  gloss  on,  451 
smooth  finished,  447-44!* 
black  varnish 
for,  44  s 
stuck  together,  a  good  way 

to  open,  451 
stuffing  for,  440,  441 
phosphine,    sample   of  leather, 
dyed  with,  568 
Patents,  list  of,  relating  to  the  manu- 
facture of  leather,  639-654 


Patterson,  S.  J.,  patent  of,  for  form- 
ing an  artificial  grain  on  the  hide, 
452,  453 

Payen's  apparatus  for  distilling  birch 
oil,  480 

Peabody,  Mass.,  manufacture  of  India 

tanned  goat  in,  364 
Peach  wood,  extract  of,  559 
Pebble  grain,  finish  for,  431 

very  bright,  431 
finishing  of,  425 
goat,  finishing  of,  373 
stuffing  for,  4ii4 
Pebbling    and    finishing  machine, 
Knox  improved  inclined  bed, 
268-271 

glassing  or  polishing,  finishing, 
rolling,  etc.,  machines  for,  263- 
272 

or  rolling  jack,  straight  bed,  266, 
267 

Peirson-Moor  process  of  depilating, 
116 

Peltries,  deer  skins  and  furs,  tanning 

of,  493,  494 
Pendulum  jack,  Coombs,  271,  272 
Pennsylvania,    varieties    of  leather 

produced  in,  4 lit 
Percolation,  55 
Petroleum,  222 

Pfanhauser,    preparation    of  basic 

ferric  sulphate  according  to,  290 
Philadelphia,  Penna.,  softening  mill 

used  in,  84,  85 
Phosphine,  patent,  sample  of  leather 

dyed  with,  568 
Phosphoric  acid,  use  of,  as  a  bate, 

164 

Phyllocitannic  acid,  45 
Picric  acid,  priming  with,  554 

green  on  leather,  557 
Pigeon  gray  on  glace  leather,  606 

production  of  modifications 
with,  575 
manure,  158 
Pin-mill,  331 

Pine  tar  and  birch  tar,  differentiation 
of,  488 

Pink  on  sheep-skins,  524,  525 
Planimeter,  Bolton,  281 
Plow  grain,  428,  429 

blacking  of,  424' 
oil  for,  429 
stuffing  for,  428 
Plumping,  173,  342 

and  handling,  167-178 
by  means  of  acetic  acid,  177,  178 
sour  liquor,  173-175 


672 


INDEX. 


Plumping  by  means  of  sulphuric  acid, 
175-177 

Pocket  book,  bag,  case,  welt  and 
strap  leather,  and  flexible  splits,  to 
dress,  (537,  638 

Pogy,  228 

Pohle  air  lift  pump,  efficiency  of  the,  17 
system  of  raising  water,  15-20 

Polishing  or  glassing,  finishing,  roll- 
ing, pebbling,  etc.,  machines  for, 
263-272 

Pompeian  red  on  glace  leather,  605 
Porpoise  oil,  229 
Potash  alum,  283 

chloride  of,  355 
Potassium  bichromate,  285,  286,  330 
and  hyposulphite  of 
soda,  determination 
of  the  proper  re- 
lation between,  354 
combinations,  285 
rule  for  finding  the 
combining  weight 
of,  352,  353 
solubility  of,  285 
chromate  and  logwood,  dyeing 

with,  610,  611 
ferrocyanide  of,  561 
permanganate,  bleaching  with, 
536 

xauthogenate,  120,  121 
Power,  electric  transmission  of,  636, 
637 

Press  leach  system,  60,  61 

Protaceae  barks,  46 

Pumping  machinery,  prominence  of, 

in  engineering,  12 
Pump,  invention  of  the,  13 
Pumps,  12-20 

and  water,  1-20 

atmospheric,  13,  14 

lilting,  13,  14 
Pure  run,  155 
Puring,  153,  378 

definition  of,  161 
Putting-out  machine,  356-358 

QUEBRACHO,  36,  44 
advantages  in  the  use  of, 
41,  569 
analysis  of,  39 
cost  of,  44 
extract,  44 

-tanned  leather,  sample  of, 
569 

with   oak  bark,  method 
for  employing,  42,  43 
Quercitron,  35 


RABBIT,  clipped,  imitation  nutria 
in  dyeing  of,  498 
skins,  black  on,  616 
dyeing  of,  497 
Raising,  88,  89 
process  of,  92 
series,  92 
Ratauky  root,  47 
Red,  alizarine,  on  leather,  556 
oak  bark,  35 

brown  to  dark  brown  on  glacd 

leather,  606 
dye  for  Russia  leather,  481 
on  cordovan  leather,  581 

genuine  Russia  leather,  580 

leather,  556 

morocco  leather,  581 

tawed  leather,  582 
ordinary,  on  leather,  557 
Pompeian  on  glace  leather,  605 
wood,  extract  of,  559 
Reddish  brown  to  Venetian  red  on 

glace  leather,  605 
Reducing,  153 

Reed  and  Winchester's  stuffing  drum, 
218-220 

Reel,  handling  by  means  of  a,  167, 168 
treating  skins  in  a,  337,  338 

Regalia  leather,  450 

enameled  leather,  patent 
leather,  furniture  or  up- 
holstering leather,  436- 
460 

Register  straps,  leather  for,  415 
Richardson,  Alpba,  patent  of,  186 
Robertson's  grinding  adjustment  for 

belt   knife   splitting  machines, 

£03-207 
Rocker  handler,  the,  108 

-motion   leather  finishing  ma- 
chine, Bowers,  263-265 
Rockers,  382 

liquors  supplied  to  the,  382,  383 

spent  liquors  from,  57 
Rolling  and  glazing  room  of  a  mo- 
rocco factory,  371,  372 

machine  for  sole  leather,  386, 
387 

or  pebbling  jack,  straight  bed, 
266,  267 

pebbling,  glassing  or  polishing, 
finishing,  etc.,  machines  for, 
263-272 
Rolls,  glazing,  615 

Rood    improved   shaving  machine, 

254,  255 
Rove,  31 
Rusma,  109 


INDEX. 


673 


Russet  harness  leather,  bleaching  of, 
537,  538 
leather,  414-417 
dyeing  of.  417 
printing  of,  41li 
Russia  calf,  470-474 

coloring  of,  473,  474 
dyed  samples  of,  5(34 
coloring  matter  for  Russia  leather 

used  in,  482 
leather,  cause  of  the  peculiar 
odor  of,  47(5 
black  colored,  484 
genuine,  color  mixtures  for, 

580,  581 
manufacture  of,  in  the  United 
States,  480- 
482 

Russian  method 
of  preparing 
and  applying 
the  mordant 
and  dye,  man- 
ufacture of 
birch  oil,  475- 
488 

red  dye  for,  4sl 

color  of,  480 
uses  of,  475 
locations  of  leather  manufactories 
in,  470 

mordant  for  Russia  leather,  used 

in,  482 
odor  to  calf  leather,  488 
oil,  484 

preparation  of  birch  oil  in,  478,  470 
Rutea,  29 

PADTLER,  Prof.  S.  P.,  experiments 
O    of,  341 
Sal,  401 

Salt,  basic  or  oxy,  313 
common,  288,  280 
Syracuse  coarse,  for  curing  hides, 
381 

Salts,  most  important,  used  in  leather 

dyeing,  554,  555 
Sammying  russet  leather,  416 
Samples  of  dyed  leathers,  564-569 
Sandstone  fdter,  Foster's,  594,  595 
Sassafras  root,  47 
Satin  grain,  stuffing  for,  422 

oil,  blacking  of,  424 
finish  for,  431 
finishing  of,  424,  425 
Saw-toothed  flesher,  136 
Sawyer's  leather  measuring  machine, 

277-279 


Scarlet  on  leather,  556,  557 

Schmitz-Dumont,  Dr.  \V.  on  deter- 
mination of  tanning  matters,  633- 
030 

Schroeder,  J.  V.,  and  Schmidt-Du- 
mont,  W.,  on  the  chemistry  of 
depilatories,  116-120 
Schultz,  Augustus,  circular  of,  347-349 
early  experiments  of, 
327 

essential  disco  very 

made  by,  339 
Wm.  M.  Norris,  on  the 

patents  of,  346,  347 
patents  of,  326 
specification    of  first 

patent  of,  343-345 
specification  of  second 

patent  of,  345,  346 
transfers  of  patents  of, 

327, 328 

Schultz's  method  of  tanning,  297,  298 
process,  tawing  skins  according 

to  the,  336-343 
two  bath  process,  207 

Scorza  rosa,  46,  47 

Scoured  leather,  preparation  of  hides 

for,  386 
Scouring,  166,  208-214 

and  setting-out  machine,  212-214 
'  indications  of  the  readiness  of 

hides  for,  139,  140 
hand  method  of,  tools  used  in  the, 

208.  209 
machine,  Monk's,  209-212 
tables  and  other  mechanical  de- 
tails of  hand  method  of,  208,  209 
Seal  and  hog,  imitation,  427,  428 

skin,    imitation   of,    in  clipped 

musk-ox,  dyeing  of,  40S 
oil,  brown,  detection  of,  in  cod 
oil,  225 
Seasoning  composition,  360 

for  straight-grained  goat,  369 
machine,  358-300 
vSepia  brown  on  glace"  leather,  006 
Setting-out,  248.'  24!) 

tables  for,  217 
Shaving  and  whitening  leather,  250- 
255 

machine,  254,  255 
Sheep  leather,   glove,    natural  tan 
sample  of,  565 
leathers,  507-525 
-skin,  dyed  sample  of,  565,  566 
flesher,  512 

fleshers,  dressing  of,  for  glove 
bindings,  513,  518,  519 


43 


674 


INDEX. 


Sheep-skin,  pickle,  dyed  sample  of, 
565, 566 
tannery,  drying  loft  in  a,  513, 
516 

exterior  view  of  a,  512, 
514 

finishing  room  in  a,  513, 
517 

tanning  vats  in  a,  513,515 
-skins,  bark  tanned,  dyeing  of, 
intense  dull  black,  525 
blue-reddish  on,  522 

-bluish  on,  522 
claret  or  maroon  on,  524 
cochineal  on,  523 
coloring  for,  522-525 
composition    for  removing 
the  hair  from,  520 
for  tanning,  520 
grass-green  on,  523,  524 
Hestahl's  process  for  dress- 
ing, 520,  521 
Hibbard's  method   for  pre- 
paring and  tanning,  520 
lemon  yellow  on,  523 
liming  of,  94 

manufacture  of,  into  lining, 
hinders  and  skivers,  512, 
513 

pink  on,  524,  525 

removal  of  grease  from,  04, 

508,  500 
scabby, 95 
solferino  on,  525 
tanning  of,  by  the  chrome 

process,  306 
tawingof,  Manasse's method, 

519 

unhairing  of,  508 
uses  of,  507,  508 
Shoe  leather,  brown,  571 

proper  wav  of  splitting, 
415,416 

purposes,  horse  hides  for,  402- 
464 

work,  dyeing  calf  skins  for,  572, 
573 

Shoes,  dyeing  of  leather  for,  571-573 
sporting,  demand  for,  303,  304 
varieties  of  colored  leather  for, 

573 

Shorea  Robusta,  401 

Short  hair  knife,  133 

Shute  and  Faulkner's  seasoning  ma- 
chine, 358-360 

Sicilian  sumach,  31 

.Side  leather,  frames  for  japanning, 
444 


Sides,  best  bate  for,  15S 

for  grain  and  split  leathers,  hand- 
ling of,  172 
handling  the,  by  means  of  a  reel, 

167,  168 
modes  of  connecting,  168 
splitting  of,  in  the  manufacture 
of  heavy  upper  leather,  188 
Sienna  brown  on  glace  leather,  605 
Silicic  acid  in  water,  recognition  of,  5 
Silk  dyeing,  application  of  the  alaza- 

rines  in,  .124 
Skin,  animal,  2I-2S 

behavior  of  the,  under  various 

conditions,  24 
chemical  and  morphological  con- 
stitution of,  24,  25 
cleansing  the,  with  borax,  52 
explanation    of    the    effect  of 
sodium  sulphide  on  the  grain 
of  the,  1-4,  105 
fibre,  most  important  property 

of,  28 
fibroin,  28 
"  killing"  the,  496 
practice  of  reducing  the,  161 
tissue,  absorption  of  alum  by  the, 
284 

transverse  section  of,  22,  23 
Skins  and  hides,  preparation  of,  for 
soaking,  79-81 
working  out  and  un- 
hairing all  kinds  of, 
without  limes,  bate, 
drench  or  beaming, 
116 

consequence  of  the  use  of  too 
concentrated  solutions  of  tan- 
nin for,  390 

depilous,  86 

final  step  in  the  process  of  tan- 
ning, 181 
oil  dressing,  American  process 

of.  232,  233 
or  hides,  art  of  tawing,  618-622 
building  for  sweating, 
121-124 

separation  of,  in  classes  for  dye- 
ing, 585,  586 
soaking  of,  79 
softening  of,  84 
sumach  tanned,  364-366 
unhairing    of,     by    the  hand 

method,  130-135 
washing  the,  for  dyeing,  580-588 
with  the  hair  on,  bleaching  of, 
540,  541 
Skirling,  curriers',  395 


INDEX. 


675 


Skivers,  binders  and  lining,  512,  513 
Slate  gray  on  glac<;  leather,  li(l7 
Slater,  the,  330,  378 
Slicker,  208 
coat,  440 
softening,  30.S 
whitening,  250 
Slocomb  &  Co.,  hand-method  stak- 
ing machine,  built  by,  273,  274 
Smiley,  R.  W.,  and  Gopelrivitch,  re- 
port of,  on  alligator  hunting,  400 
Smith,  Olive  r  C,  patents  of,  251 
Smooth  finished  patent  leather,  447- 
449 

leather,  black 
varnish  for, 
448 

Smutting,  433 

off  or  bleeding  of  colors,  563,  504 
Snouba  hark, 40,  47 
Soak,  chemical,  82 
Soaking  and  softening,  78-85 

final,  before  placing  the  hides  in 

the  ooze,  166 
hides  after  fleshing  by  the  hand 
method,  138,  139 
in  a  steeping   cistern  after 
fleshing,  139 

Soaks,  330 

change  of  water  in  the,  370 
use  of  pure  water  in  the,  83 
Soap,  Palermo  fig,  stuffing  or  fat- 
liquoring  with,  242.  -  \'-'> 
solution    for    determining  the 
hardness  of  water,  0 
Soaps  555 

Sod  oil,  American,  233 
artificial,  234 

conversion  of  fish  oil  to,  by 

oxidation,  2 ">4 
early  use  of,  231 
English,  220,  227 
European,  233 
French,  233 

pure,  tanning  principle  of,  234 
sulphuric  acid  in,  231 
Soda,  hyposulphite  of,  287 

use  of,  for  softening  water,  593, 
594 

Sodium  bichromate,  280 

peroxide,  bleaching  with,  535 
sulphide,  advantages  of,  99 
depilating  with,  97-113 
effect  of,  in  the  limes,  104 
explanation  of  the  effect  of, 
on  the  grain  of  the  skin, 
104,  105 
grades  of,  98,  99 


Sodium  sulphide,  improved,  100 

in   connection  with  lime, 

method  of  using,  98 
method  of  using,  102,  1(13 
plumping  properties  of,  100 
properties  of,  100 
results  obtained  by,  111 
summary  of  the  good  quali- 
ties of,  105 
undesirable  qualities  of,  105- 
107 

Softening,  S4,  to 

and  soaking,  78-85 

machine,  Tidd's,  549-552 

mil  fused  in  Philadelphia,Penna., 

84,  85 
slicker,  368 
Sole  leather,  American,  export  trade 
in,  to  Germany,  40 
analysis  of  a  sample  of, 

489,  490 
bate  for,  100,  161 
bating  the  hides  for,  381 
chrome  tannage  for,  302 
drying  of,  385 
layers  and  periods  for,  182 
liming  of,  380,  381 
method     for  employing 
quebracho  with  oak  bark 
for,  42,  43 
oak  tanned, laying  away  the 
packs  of,  1 82 
schedule  of  the  time 
and  strength  of 
liquor  employed 
in  each  layer  for, 
383,  ?84 
unscoured  and 
scoured  leather, 
cut  soles,  379-389 
process    for    using  pure 
quebracho  wood  for,  in 
Buenos  Ayres,  41,  42 
rolling  machine  for,  386, 
387 

scudding  the  grain  of,  381 
situation    in    the  United 

States,  43 
softening  dry  hides  for,  82 
Soles,  cut,  387-389 
Solferino  on  sheep-skins,  525 
Solutions,  theory  of,  570,  577 
Sorting  leather  for  dyeing,  585,  5S6 
Sour  liquor,  plumping  by  means  of, 
173-175 

liquors,  distillation  of,  174,  175 
South  American  hides,  379 
Spanish  sumach,  32 


676 


INDEX. 


vSplit  and  grain  leather,  418-435 
frames,  444 

leather,  handling  of  sides  for,  172 
preparing  the  cut  surface  of, 
for  manufacturing  japan- 
ned or  enameled  leather, 
452,  453 
Splitting  card  leather,  416 
leather,  186-207 

hints  for,  193,  194 
leathers,   instructions  in  regard 

to,  198-200 
machines,  186-198 
shoe  leather,  proper  way  of,  415, 
416 

strap  leather,  41<i 
Splits,  blacking  for,  427 

crimping,  finishing  of,  425,  426 

flesh,  429-432 

flexible,  433-435 

to  dress,  637,638 

kinds  of  leather  derived  from,  444 

trimming  of,  421 

upper,  paste  for,  427 
Sporting  shoes,  demand  for,  303,  204 
Spring  fleshers,  136 

water,  admixtures  of,  2 
Stag's  leather,  bleaching  of,  537,  538 
Stain  for  grain  and  split  leather,  424 
Staking  machine,  273-276 
Stakpole  staking  machine,  274,  275 
Starcke,  Dr.  H.  E.,  analysis  of  spent 

bark  by,  65 
Steam  jacket  kettles,  242 
Stearin,  223 

Steel  gray  on  glace  leather,  <il!7 
Stevens,  John  W.,  on  the  sulphide  of 

sodium  process,  100-102 
Stone,  the,  208 
Stoning,  185,  217,  218 
jack,  185,  415 

-out,   scouring  and  setting-out 
machine,  248,  249 
Straight  bed  rolling  or  pebbling  jack, 
266,  267 

-grained  goat,  finishing  of,  368- 
373 

Straits,  bank  or  menhaden  oil,  228- 
229 

oil,  tanning  principle  of,  234 
Strap  butts  for  mill  bands  and  engine 
belts,  currying  of,  407,  408 
leather,  414 

drum  tannage  for,  399,  400 
splitting  of,  416 
pocket  book,  bag,  case  and  welt 
leather  aud  flexible  splits,  to 
dress,  637,  638 


Straps  for  street  cars,  leather  for,  515 
Stretching  hides,  mechanical  devices 
for,  543,544 
machine,  Coupe's,  547-549 
Striking  out,  object  of,  364 
Strontium  chromate,  286 
Stuffing,  best  material  to  use  in,  216 
drum,  216-218 
Freeman's,  221 

Reed  and  Winchester's,  218- 
220 

for  dongola,  424 

enameled  or  patent  leather, 
440,  441 

flesh  splits,  429 

glove  grain,  422,  424 

imitation  goat  grain,  424 

kangaroo,  424 

pebble  grain,  424 

plow  grain,  428 

satin  grain,  422 

upper  leather,  227 
hand  method,  objections  to,  215, 
216 

leather;  oils  and  fats;  testing  oils; 
water-proof    stuffing  ;  water- 
proofing leather,  215-247 
water-proof,  243 
with  glycerine,  239,  240 
with  Palermo  fig  soap,  242,  243 
Sugar,  testing  leather  weighted  with, 
489 

Sulphate  of  alumina,  561 

copper,  561 
Sulphates  in  water,  recognition  of,  5 
Sulphuric  acid  in  water,  recognition 
of,5 
for  bate,  164 

toning  down,  539 
free,    detection    of,  in 
aluminium  sulphate, 
283 

plumping  by  means  of, 

175-177 
properties  of,  176,  177 
Sulphurous  acid,  apparatus  for  the 
production   of,  534, 
535 

bleaching  with,  532- 
534 

control  of,  355 

Sumac,  31,  32 

tanned  skins,  364-366 
Sweat  box,  construction  of  the,  127 
Sweating,  depilating  by,  120,  121 

fresh  hides,  128,  129 

hides,  care  to  be  observed  in, 
124-127 


INDEX. 


677 


Sweating  process,  warm,  127,  128 
Swedish  sumach,  32 
"Sweet  meats,"'  445 
Symbols,  chemical,  351,  352 
Syracuse  coarse  salt  for  curing  hides, 
381 

'FALLOW,  227 

1     machine  belt  leather,  greased 

with,  405,  400 
Tan  leather,  water- proofing  of,  247 
press,  71-73 

vat  used  in  the  two-bath  method 
of  chrome  tannage,  343 
Tannage,  drum,  399,  400 

chrome  or  mineral,  289-304 

some  patents  for,  300-308 
for  grain  and  split  leathers,  410 
systems,  electric  and  other  rapid, 
520-531 

Tanners'   preparation  for  obtaining 

uniform  colored  leather,  562.  563 
Tanner's  pump.  12 
Tanneries,  location  of,  1 

modern,  fitting  up  of,  530 
Tannery,  sheep-skin,  drying  loft  in  a, 
513,516 
exterior  view  of  a,  | 

512,514 
finishing  room  in  a, 

513,517 
tanning  vats  in  a, 
513.515 
Tannin,  action  of,  179 

and  logwood,  dyeing  with,  611 

iron  salts,  dyeing  with,  610 
combination  of  glycerine  with  ,239 
Tanning  and  dyeing  furs  and  hair 
skins,  491- 500 
calf-skins  in  the  hair,  491,  402 
calf  or  goat-skins  by  the  chrome 

process,  304-306 
Dennis  method  of,  298-300 
extract,  decolorizing  process  in 

the  preparation  of,  77 
extracts,  74-77 

examination  of,  77 
leather,  Dennis  process  of,  313- 
319 

liquor,  Dennis,  308-313 
material     for    Indian  harness 

leather,  401,  402 
materials,  vegetable,  29-47 
matters,  determination  of,  033- 

636 

mineral,  antiquity  of,  282 
process     for     Indian  harness 
leather,  402,  403 


ning  process,  nature  of  the,  591 
quick,  for   harness  leather, 
392 

processes,  quick,  revolution  in, 

527,528 
quick,  use  of  borax  in,  52 

with    chromates,  Heinzer- 
ling's  patent  for,  293-296 
Schultz's  method  of,  297,  298 
sheep-skins  by  the  chrome  pro- 
cess, 306 
substances,    mineral,  principal, 
282 

vats  in  patent  leather  factory,  438 
sheep-skin  tannery,  513, 
515 

Zahn's  patent  for,  349-351 
Tanolin,  298,  299 

directions  for  using  on  calf  or 
goat-skins,  304-306 
Tawed  leather,  color  mixtures  for, 
581,  582 
dyeing  of,  598 
not  dyed,  glazing  of,  613 
sorting  of,  for  dyeing,  585 
washing  of,  fordveing,  586, 
587 

Tawing,  336-343 

hides  of  skins,  art  of,  618-622 
lamb  and   kid  skins  for  glove 

leather,  dyeing,  501-504 
sheep-skins,  Manasse's  method 
for,  519 
Tempering.  215 
Terra  japonica,  29,  30 
Testing  oils,  240,  241 
Tests  of  new  Indian  harness  leather, 

404,  405 
Texas  hides,  379 
Tezera  sumach,  32 
Thibet,  dark  brown  for,  497 
Tidd's  softening  machine,  549-552 
Tin  salt,  preparation  of  a  mordant  of, 

575,  576 
Toning  fluids,  578-580 

action  of,  578,  579 
and  dyes,  603.  604 
preparation  of,  579,  580 
Top  leather,  black  enameled,  444- 
447 

Tormentil  root,  47 

Towein's  graining  machine,  483 

Tramping  drums,  improvement  in, 

220.  221 
True  skin,  21,  22 
Tub  wheel,  the,  543 
Tumbling  barrel,  soaking  hides  in,  78 
Tunny  oil,  229 


678 


INDEX. 


Turning  steel,  three  square,  137 
Tyrol  sumach,  32 

UNDER  SKIN,  constitution  of.  22 
Unhairing  and  fleshing  by  hand 
a  n  d     in  a- 
c  h  i  n  e  r  v, 
130-152 
by  machinery, 

140-152 
in  achines, 
practical 
success  of, 
151 

knife,  130 
machines,  140-148 
methods    for  accomplish- 
ing, 86 
or  depilation,  8G-129 
Union  leather,  cloudy  and  dirty.  38J 
measuring  machine,  27'.i- 
281 

splitting  machine,  188 

hints  with   the  use 
of  the,  103,  1(14 

tannage,  34 

whitening  and  buffing  machine, 
251-254 

United  States,  bating  dressing  leather 
in  the,  100 
leather  situation  in  the,  1:1 
list  of  patents  relating  to 
the     manufacture    o  f 
leather  issued  by  the, 
639-651 
location  of  tanneries  and 
currying  shops  in  the,  1 
mail  bags,  leather  for,  414 
manufacture     of  Russia 

leather  in  the,  480-482 
tanning  extracts  in  com- 
mon use  in  the,  74 
Unscoured  and  scoured  leather,  oak- 
tanned  sole  leather,  cut  soles,  379- 
389 

Upholstering  or  furniture  leather,  fin- 
ishing of,  44!) 
leather,  regalia 
enameled 
leather,  patent 
leather,  436- 
460 

Upper  leather,  bate  for  hides  for,  140 
chrome,  .".111 

heavy,  practice  of  hand- 
ling, 184 

lime  for  green  hides  and 
kips  for,  399 


Upper  leather,  requisite  qualities  of, 
418 

stuffing  for,  227 
tannery,  cellar  of  an,  186 
drying  yard  of  an,  422, 
423 

whitening  of,  250 
splits,  paste  for,  427 
Uppers,  burnt,  .'102 
Ursol  colors,  495 

advantage  in  dyeing  with, 
499 

blue-black  tinge  with,  IMS, 
499 

\7ACIIE   leather,    preparation  of, 
397-399 
Valonia,  32,  33 

Varnish,  black,  preparation  of,  44S 
brushes,  451 
enameled,  446 

finishing    for    smooth  finished 
patent  leather,  449 
Vaseline,  use  of,  for  rendering  leather 

pliable,  015 
Vats,  lay-away,  181,  383 
Vaughn    Machine  Co.,  bark-cutter 
made  by  the, 
66,  67 
breaking,  flesh- 
ing, unhairing 
and  slating 
machine  made 
by    the,  331, 
333,  334 
Coombs  pendu- 
lum jack  made 
by  the,  27 1.272 
improved  flesh- 
ing, unhairing 
and  working- 
out  machine 
of  the,  14H-1  15 
leach    p  u  m  p  s 
made  bv  the, 
52 

putting-out  ma- 
chine built  by 
the,  356-358 

Rood  improved 
shaving  ma- 
chine, man- 
ufactured l>V 
the,  254,  255 

scouring  a  n  d 
s  e  1 1  i  n  g-o  u  t 
machine,  built 
by  the,21  2-214 


INDEX. 


679 


Vaughn  Machine  Co.,  staking  ma- 
chine built  by 
the,  274,  275 
s  t  o  n  i  n  g-o  u  t, 
scouring  and 
setting- out 
machine, built 
bythe,248,249 
wet  stretching 
machine  for 
belt  leather, 
made  bv  the, 
'  409-411 
Vegetable  tanning  materials,  29-47 
Velocitan  process  of  quick  tannage, 
527 

Vickers'  degras,  231 
Villon,  experiments  by,  120,  121 
Violet  on  tawed  leather,  5S2 
Vitriol,  oil  of,  properties  of,  1 70,  177 

fALNUT  bark,  45 

Warm  sweat  method,  121,  127, 
128 

Warrington,  use  of  carbonate  of  am- 
monia as  a  bate  by,  104 
Wash  mill,  377 

Washing  and  bating,  vats  and  wheels 

for,  1G5 
leather,  rules  for,  592 
machine,  the,  588-590 
Water,  analysis  of,  from  the  Ganges 

canal,  401 
and  pumps,  1-20 
borax  for  softening,  83,  594 
degrees  of  hardness  of,  9 
for  dyeing,  quality  of  the,  593- 

595 

gases  held  in  solution  in,  2 
hard,  2,  593 

importance  of  the  chemical  con- 
stitution of,  593 

important  position  of,  in  tan- 
ning, 1 

methods    for    determining  the 

constituents  of,  4-9 
most  important  admixtures  of, 

1-3 

organic  products  of  decomposi- 
tion in,  2,  3, 
per  cent,  of,  in  degras,  (132,  633 
permanent  hardness  of,  determi- 
nation of,  II 
-pit,  78 

arranging  hides  in  the,  79 
l'ohle  system  of  raising,  15-20 
points  to  be  considered  in  de- 
termining the  qualities  of,  3 


Water-proof  colors,  560,  5G1 
stuffing,  244 
-proofing  leather,  215-217 

compound  for,  240 
qualitative  examinations  of,  4-9 
sandstone  filter  for,  594.  595 
soda  for  softening,  593,  594 
soft,  2 

softening  of,  9-12 
solvent  properties  of,  11,  12 
stripes,  production  of,  395 
temperature  of  the,  for  prepar- 
ing the  bides,  4 
total  hardness  of,  determination 
of,  6-8 

variation  in  the  boiling  point  of, 
76 

Waters,  natural,  influence  of,  upon 
corii'n,  2(i 

Wax  finish  on  chrome-tanned  horse 
hide  butts,  4ti4 
paraffine,  235,  23(1 
stock,  paste  for,  427 
Waxed  calf,  quality  of  the  water  in 
the  manufacture  of,  18 
temperature  of  the  water  in 
the  manufacture  of,  15 
Weighting  of  leather,  489,  490 
Wi  ights  and  measures,  500 
Weld,  34 

Welt,  strap,  pocket  book,  bag  and 
case  leather,  and  flexible  splits  to 
dress,  637,  638 
Well  water,  admixtures  of,  2 
Wet   stretching   machine    for  belt 

leather,  409-411 
Wheels,  soaking  hides  in,  78 
Whip  and  lace  leather,  quick  tanning 

process  for,  540,  547 
Whipstocks,  leather  for,  414 
White  leather,  511 

bluing  of,  536,  537 
oak  bark,  35 
Whitening    and    buffing  machine, 
Union,  251-254 
shaving  leather, 
250-255 

slicker,  250 
Whitney's  "Jumbo  "  unhairing  ma- 
chine, 140,  147 

patent  combined  unhairing, 
fleshing  and  working-out  ma- 
chine, 147-149 

patent  re-fleshing  machine,  149, 
150 

Wild  goat,  dark  brown  for,  -197 
grey-brow n  for,  497.  198 
Willow  bark,  40 


68o 


INDEX. 


Willow  tannage  for  Danish  leather, 
412 

Wisconsin,  varieties  of  leather  pro- 
duced in,  4 HI 
Wood  brown  to  mahogany  color  on 
glace  leather,  605 
dyes,  advantage  of,  558 
Wool  waste,  American  degras  from, 

631,  632 
Worker,  the,  137 

Worms,  E.,  tanning  process  of,  5i'(i 

YELLOW,  barberry,  on  leather,  557 
chrome,  on  leather,  557 
lemon,  on  leather,  557 
light  ochre,  on  glace  leather,  604 


Yellow  maize,  on  glac£  leather,  <J0l 
on  cordovan  leather,  581 

morocco  leather,  581 

tawed  leather,  582 
Yolk  of  egg,  preservation  of,  ~)!)7 
Young  fustic,  559 

ZAHN,  W.,  first  production  of  com- 
mercial leather  tanned 
by  Schultz's  process  by, 
298 

patent,  specification  of  the, 
349-351 

Zane,  Oliver  A.,  bark  conveyor  in- 
vented by,  68-71 


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Their  Practical  Preparation,  Purification  and  Employment;  their 
Properties,  Adulteration  and    Examination.    94  illustrations.  8vo. 

$4.00 

ARLOT. — A  Complete  Guide  for  Coach  Painters  : 

Translated  from  the  French  of  M.  Ari.ot,  Coach  Tainter,  for 
eleven  years  Foreman  of  Painting  to  M.  Eherler,  Coich  Maker, 
Paris.  By  A.  A.  FESQUET,  Chemist  and  Engineer.  To  which  is 
added  an  Appendix,  containing  Information  l*esoecting  the  Materials 
and  the  Practice  of  Coach  and  Car  Painting  . — J  Varnishing  in  the 
United  States  and  Great  Britain     '2mo.  .       .       .  $1.25 

(0 


2  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


ARMENGAUD,  AMOROUX,  AND  JOHNSON.— The  Practi- 
cal  Draughtsman's  Book  of  Industrial  Design,  and  Ma- 
chinist's and  Engineer's  Drawing  Companion  : 

Forming  a  Complete  Course  of  Mechanical  Engineering  and  Archi 
tectural  Drawing.  From  the  French  of  M  Armengaud  the  elder, 
Prof,  of  Design  in  the  Conservatoire  of  Arts  and  Industry,  Paris,  and 
MM.  Armengaud  the  younger,  and  Amoroux,  Civil  Engineers.  Re- 
written and  arranged  with  additional  matter  and  plates,  selections  from 
and  examples  of  the  most  useful  and  generally  employed  mechanism 
of  the  day.  By  William  Johnson,  Assoc.  Inst.  C.  E.  Illustrated 
by  fifty  folio  steel  plates,  and  fifty  wood-cuts.    A  new  edition,  410  , 

cloth  $6.00 

ARMSTRONG.— The  Construction  and  Management  of  Steam 
Boilers  : 

By  R.  Armstrong,  C.  E.  With  an  Appendix  by  Robert  Mallet, 
C.  E.,  F.  R.  S.    Seventh  Edition.    Illustrated.    1  vol.  121110.  .60 

ARROWSMITH.— Paper-Hanger's  Companion : 

A  Treatise  in  which  the  Practical  Operations  of  the  Trade  are 
Systematically  laid  down :  with  Copious  Directions  Preparatory  to 
Papering;  Preventives  against  the  Effect  of  Damp  on  Walls;  the 
various  Cements  and  Pastes  Adapted  to  the  Several  Purposes  01 
the  Trade ;  Observations  and  Directions  for  the  Panelling  and 
Ornamenting  of  Rooms,  etc.  By  James  Arrowsmith.  J2mo., 
cloth  $1.00 

ASHTON. — The  Theory  and  Practice  of  the  Art  of  Designing 
Fancy  Cotton  and  Woollen  Cloths  from  Sample  : 

Giving  full  instructions  for  reducing  drafts,  as  well  as  the  methods  of 
spooling  and  making  out  harness  for  cross  drafts  and  finding  any  re- 
quired reed;  with  calculations  and  tables  of  yarn.  By  FREDERIC  T. 
AsHTON,  Designer,  West  Pittsfield,  Mass.  With  fifty-two  illustrations. 
One  vol.  folio   #5-°° 

ASKINSON. — Perfumes  and  their  Preparation: 

A  Comprehensive  Treatise  on  Perfumery,  containing  Complete 
Directions  for  Making  Handkerchief  Perfumes,  Smelling  Salts, 
Sachets,  Fumigating  Pastils ;  Preparations  for  the  Care  of  the  Skin, 
the  Mouth,  the  Hair;  Cosmetics,  Hair  Dyes,  and  other  Toilet 
Articles.  By  G.  W.  AsKINSON.  Translated  from  the  German  by  IsiDOR 
Furst.    Revised  by  Charles  Rice.    32  Illustrations.   8vo.  #3.00 

BRONGNIART. — Coloring  and  Decoration  of  Ceramic  Ware. 
8vo.   $2.0O 

BAIRD  — The  American  Cotton  Spinner,  anc  Manager's  and 
Carder's  Guide: 
A  Practical  Treatise  on  Cotton  Spinning ;  giving  the  Dimensions  and 
Speed  of  Machinery,  Draught  and  Twist  Calculations,  etc. ;  with 
notices  of  recent  Improvements:  together  with  Rules  and  Example-- 
ror  making  changes  in  the  sizes  and  numbers  of  Roving  and  Yarn. 
Compiled  from  the  papers  of  the  late  Robert  H.  Baird.  I2nio. 

#■1.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


3 


BAIRD.— Standard  Wages  Computing  Tables  : 

An  Improvement  in  all  former  Methods  of  Computation,  so  arranged 
that  wages  for  days,  hours,  or  fractions  of  hours,  at  a  specified  rate 
per  day  or  hour,  may  be  ascertained  at  a  glance.    l!y  T.  Spangler 

Baird.    Oblong  folio  $5.00 

BAKER. — Long-Span  Railway  Bridges: 

Comprising  Investigations  of  the  Comparative  Theoretical  and 
Practical  Advantages  of  the  various  Adopted  ur  Proposed  Type 
Systems  of  Construction ;  with  numerous  Formulae  and  Tables.  By 

B.  Baker.    i2mo.   $1.00 

BAKER.— The  Mathematical  Theory  of  the  Steam-Engine: 
With  Rules  at  length,  and  Examples  worked  out  for  the  use  of 
Piactical  Men.    By  T.  Baker,  C.  E.,  with  numerous  Diagrams. 
Sixth  Edition,  Revised  by  Prof.  J.  R.  YoUNG.    I2mo.        .  75 
BARLOW.— The    History   and   Principles  of  Weaving,  by 
Hand  and  by  Power: 
Reprinted,  with  Considerable  Additions,  from  "  Engineering,"  with 
a  chapter  on  Lace-making  Machinery,  reprinted  from  the  Journal  of 
the  "Society  of  Arts."  By  Alfred  Barlow.  With  several  hundred 
illustrations.    8vo.,  443  pages  .....  JjSlo.oo 

BARR. — A  Practical  Treatise  on  the  Combustion  of  Coal: 
Including  descriptions  of  various  mechanical  devices  for  the  Eco- 
nomic Generation  of  Heat  by  the  Combustion  of  Fuel,  whether  solid, 
liquid  or  gaseous.    8vo.    .......  $2.50 

BARR. — A  Practical  Treatise  on  High  Pressure  Steam  Boilers: 
Including  Results  of  Recent  Experimental  Tests  of  Boiler  Materials, 
together  with  a  Description  of  Approved  Safety  Apparatus,  Steam 
Pumps,  Injectors  and  Economizers  in  actual  use.    By  Wm.  M.  Barr. 

204  Illustrations.    8vo.     .   $3.00 

BAUERMAN.— A  Treatise  on  the  Metallurgy  of  Iron: 

Containing  Outlines  of  the  History  of  Iron  Manufacture,  Methods  of 
Assay,  and  Analysis  of  Iron  Ores,  Processes  of  Manufacture  of  Iron 
and  Steel,  etc.,  etc.  By  H.  Bauerman,  F.  G.  S.,  Associate  of  the 
Royal  School  of  Mines.  Fifth  Edition,  Revised  and  Enlarged. 
Illustrated  with  numerous  Wood  Engravings  from  Drawings  by  J.  B. 

Jordan.    i2mo   ...  $2.oc 

BRANNT. — The  Metallic  Alloys:  A  Practical  Guide 

For  the  Manufacture  of  all  kinds  of  Alloys,  Amalgams,  and  Solders, 
used  by  Metal  workers;  together  with  their  Chemical  and  Physical 
Properties  and  their  Application  in  the  Arts  and  the  Industries;  with 
an  Appendix  on  the  Coloiing  of  Alloys  and  the  Recovery  of  Waste 
Metals.  By  William  T.  Brannt.  34  Engravings.  A  New,  Re- 
vised, and  Enlarged  Edition.  554  pages.  8vo.  .  .  $4 .50 
BEANS.— A  Treatise  on  Railway  Curves  and  Location  of 
Railroads : 

By  E.  W.  Beans,  C.  E.    Illustrated.    i2mo.    Tucks      .  $i.So 
BECKETT.— A  Rudimentary  Treatise  on  Clocks,  and  Watches 
and  Bells  : 

By  Sir  Edmund  Beckett,  Bart.,  LL.  D.,  Q.  C.  F.  R.  A.  S.  With 
numerous  illustrations.  Seventh  Edition,  Revised  and  Enlarged. 
i2mo   J1.80 


4  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


BELL. — Carpentry  Made  Easy: 

Or,  The  Science  and  Art  of  Framing  on  a  New  and  Improved 
System.  With  Specific  Ins  ructions  for  Building  Balloon  Frames,  Barn 
Frames,  Mi  1  Frames,  Warehouses,  Church  Spires,  etc.  Comprising 
also  a  System  of  Bridge  Building,  with  Bills,  Estimates  of  Cost,  and 
valuable  Tables.    Illustrated  by  forty-four  plates,  comprising  aeaily 


200  figures.    By  William  E.  Bell,  Architect  and  Practical  Builder. 

8vo.  $5-oa 

8EMROSE. — Fret-Cutting  and  Perforated  Carving: 

With  fifty-three  practical  illustrations.    By  W.  Bemrose,  Jr.    i  vol. 
quario      .       .       .       .  .       .       .       ...  $2.50 

BEMROSE. — Manual  of  Buhl-work  and  Marquetry: 

With  Practical  Instructions  for  Learners,  and  ninety  colored  design-. 
By  \V.  Bemrose,  Jr.    i  vol.  quarto         ....  #3.00 

BEMROSE.— Manual  of  Wood  Carving: 


Wiih  Practical  Illustrations  for  Learners  ol  the  Art,  and  Original  and 
Selected  Designs.  By  William  Bemrose,  Js.  vVith  an  Intro 
duction  by  Llewellyn  Jewitt,  F.  S.  A.,  etc.  With  128  illustra- 
tions, 4to.        .........  $2.50 

BILLINGS. — Tobacco : 

Its  History,  Variety,  Culture,  Manufacture,  Commerce,  and  Various 
Modes  of  Use.  By  E.  R.  Billings.  Illustrated  by  nearly  200 
engravings.    8vo.     ........  $300 

BIRD. — T>e  American  Practical  Dyers'  Companion: 
Comprising  a  Description  of  the  Principal  Dye-Stuffs  and  Chemicals 
used  in  Dyeing,  their  Natures  and  Uses;  Mordants,  and  How  Made; 
with  the  best  American,  Engli-h,  French  and  German  processes  for 
Bleaching  and  Dyeing  Silk,  Wool,  Cotton,  Linen,  Flannel,  Felt. 
Dress  Goods,  Mixed  and  Hosiery  Yarns,  Feathers,  Gra~s,  Felt,  Fur, 
Wool,  and  Straw  Hats,  Jute  Yarn,  Vegetable  Ivory,  Mats,  Skins, 
Furs,  Leather,  etc.,  etc.  By  Wond,  Aniline,  and  other  Processes, 
together  with  Remarks  on  Finishing  Agents,  and  Instructions  in  the 
Finishing  of  F.ibrics,  Substitutes  (or  Indigo,  Water- Proofing  of 
Materials,  Tests  and  Purification  of  Water,  Manufacture  of  Aniline 
and  other  New  Dy  Wares,  Harmonizing  Colors,  etc.,  etc. ;  embrac- 
ing in  all  over  Soo  Receipts  for  Colors  and  Shades,  accompanied  by 
170  Dyed  Samples  of  Raw  Materials  and  Fabrics.  By  F.  J.  Bird, 
Practical  Dyer.  Author  of  "  The  Dyers'  Hand-Book."   8vo.  J57.50 

BLINN.— A  Practical  Workshop  Companion  for  Tin,  Sheet- 
Iron,  and  Copper-plate  Workers  : 
Containing  Rules  for  describing  various  kinds  of  Patterns  used  by 
Tin,  Sheet-Iron  and  Copperplate  Workers;  Practical  Geometry; 
Mensuration  of  Surfaces  and  Solids;  Tables  of  the  Weights  of 
Metals.  Lead-pipe,  etc.;  Tables  of  Areas  and  Circumference} 
of  Circles;  fa  pan,  Varnishes.  Lackers,  Cements,  Comix  sitions.  etc., 
etc.  By  Lerov  J.  Blinn,  Master  Mechanic.  With  One  Hundred 
M.d  Seventy  Illustrations.     121110.    .....  $2.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


5 


BOOTH  — Marble  Worker's  Manual: 

Containing  Practical  Information  respecting  Marbles  in  general,  theit 
Cutting,  Working  and  Polishing;  Veneering  of  Marble;  Mosaics; 
Composition  and  Use  of  Artificial  Marble,  Sluccos,  Cements,  Receipts, 
Secreis,  etc.,  etc.  Translated  from  the  French  by  M.  L.  Booth. 
With  an  Appendix  concerning  American  Marbles.  I2mo.,  cloth  Si. 50 
BOOTH  and  MORFIT.— The  Encyclopaedia  of  Chemistry, 
Practical  and  Theoretical  : 
Embracing  its  application  to  the  Arts,  Metallurgy,  Mineralogy, 
Geology,  Medicine  and  Pharmacy.  By  Jamks  C.  Pooth,  Melter 
and  Refiner  in  the  United  States  Mint,  Professor  of  Applied  Chem-i 
tstry  in  the  Franklin  Institute,  etc.,  as>isted  by  Campbell  MoRi-ny 
author  of  "Chemical  Manipulations,"  etc.  Seventh  Edition.  Com- 
plete in  one  volume,  royal  8vo.,  978  pages,  with  numerous  wood-cuts 
and  other  illustrations       .......  $3-5° 

BR  AM  WELL. — The  Wool  Carder's  Vade-Mecum* 

A  Complete  Manual  of  the  Art  ol  (  arding  Textile  Fabrics.    By  W. 
C.  B  RAMWELL.    Third  Edition,  revised  and  enlarged.  .Illustrated. 
Pp.  400.    I2mo.      ........  $2.50 

BRANNT. — A  Practical  Treatise  on  Animal  and  Vegetable 
Fats  and  Oils  • 

Comprising  both  Fixed  and  Volatile  Oils,  their  Physical  and  Chem- 
ical Properties  and  Uses,  the  Manner  of  Extracting  ami  Refining 
them,  and  Practical  Rules  for  Testing  them  ;  as  well  as  the  Manulac- 
tnre  of  Artificial  Butter  and  Lubricants,  etc  ,  with  lists  of  American 
Patents  relating  to  the  Extraction.  Rendering,  Refilling,  Decomposing, 
and  Bleaching  of  Pats  and  Oils.    By  William  T.  Bkannt,  Editor 
of  the  "  Techno  Chemical  Receipt  Book."    Second  Edition,  Revised 
and  in  a  great  port  Rewritten.    Illustrated  l>y  302  Engravings.  In 
Two  Volumes.    1304  pp.    8vo.     .....  #10.00 

BRANNT. — A  Practical  Treatise  on  the  Manufacture  of  Soap 
and  Candles  : 

Based  upon  the  most  Recent  Experiences  in  the  Practice  and  Science  ; 
comprising  the  Chemistry,  Raw  Materials,  Machine -v.  and  Utensils 
and  Various  Processes  of  Manufacture,  including  a  great  variety  of 
formulas.  Edited  chiefly  from  the  German  of  Dr  C.  Deite,  A. 
Engelhardt,  Dr.  C.  Schaedler  and  others;  with  additions  and  lists 
of  Ameiican  Patents  rei  ning  to  lhe»e  subjects.  By  WM.  T.  BRANNT. 
Illustrated  by  103  engravings.    677  pages.    8vo.     .       .  JS7.50 

BRANNT. — India  Rubber.  Gutta  Percha  and  Balata  : 

Occurrence,  Geographical  Distribution,  and  Cultivation,  Obtaining 
and  Preparing  the  Raw  Materials,  Modes  of  Working  and  Utilizing 
them.  Including  Washing,  Maceration,  Mixinrr,  Vulcanizing.  Rubber 
and  Gutta-Percha  Compounds,  Utilization  of  \Vaste,  etc.  Bv  Will- 
iam T.  Brannt.    Illustrated.    i2mo.  (1900.)  .  $\oc 


6  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


BRANNT — WAHL. — The  Techno- Chemical  Receipt  Book: 

Containing  several  thousand  Receipts  covering  the  latest,  most  M 
portant,  and  most  useful  discoveries  in  Chemical  Technology,  an( 
their  Practical  Application  in  the  Arts  and  the  Industries.  Editec 
chiefly  from  the  German  of  Drs.  Winckler,  Eisner,  Heintze,  Mier- 
zinski,  Jacobseu,  Roller,  and  Heinzerling,  with  additions  by  Wm.  1. 
Brannt  and  Wm.  H.  Wahl,  Ph.  D.    Illustrated  by  78  engravings. 

:2mo.    495  pages    .        .   52.o» 

ROWN. — Five  Hundred  and  Seven  Mechanical  Movements: 
Embracing  all  those  which  are  most  important  in  Dynamics,  Hy- 
draulics, Hydrostatics,  Pneumatics,  Steam-Engines,  Mill  and  other 
Gearing,  Presses,  Horology  and  Miscellaneous  Machinery;  and  in- 
cluding many  movements  never  before  published,  and  several  of 
which  have  only  recently  come  into  use.  By  Henry  T.  Brown. 
i2mo  $1.00 

BUCKM ASTER.— The  Elements  of  Mechanical  Physics: 
By  J.  C.  Buckmaster.      Illustrated  with  numerous  engravings. 
121110.       ..........  $1.00 

BULLOCK.— The  American  Cottage  Builder  : 
A  Series  of  Designs,  Plans  and  Specifications,  from  $200  to  $20,000, 
for  Homes  for  the  People ;  together  with  Warming,  Ventilation, 
Drainage,  Painting  and  Landscape  Gardening.  By  John  Bullock, 
Architect  and  Editor  of  "  T'ae  Rudiments  of  Architecture  and 
Building,"  etc.,  etc.    Illustrated  by  75  engravings.    8vo.  $2.50 

BULLOCK.— The  Rudiments  of  Architecture  and  Building: 
For  the  use  of  Architects,  Builders,  Draughtsmen,  Machinists,  En- 
gineers and  Mechanics.    Edited  by  John  Bullock,  author  of  "The 
American  Cottage  Builder."  Illustrated  by  250  Engravings.  8vo.g2.50 

BURGH. — Practical   Rules   for  the  Proportions  of  Modern 
Engines  and  Boilers  for  Land  and  Marine  Purposes. 
By  N.  P.  Burgh,  Engineer.    i2mo.         ....  $1.50 

BYLES. — Sophisms   of    Free   Trade   and    Popular  Political 
Economy  Examined. 
By  a  Barrister  (Sir  John  Barnard  Byles,  Judge  of  Common 
Pleas).      From  the  Ninth  English  Edition,  as  published   by  the 
Manchester  Reciprocity  Association.     l2mo.     .       .       .  $1.25 

BOWMAN. — The  Structure  of  the  Wool  Fibre  in  its  Relation 
to  the  Use  of  Wool  for  Technical  Purposes : 
Being  the  substance,  with  additions,  of  Five  Lectures,  deliverea  at 
'.he  request  of  the  Council,  to  the  members  of  the  Bradford  Technical 
College,  and  the  Society  of  Dyers  and  Colorists.  Bv  F.  II.  Bow- 
man, D.  Sc.,  F.  R.  S.  E.,  F.  L.  S.  Illustrated  by  32  engravings. 
8vo  f^'oo 

I  YRNE. — Hand-Book  for  the  Artisan,  Mechanic,  and  Engi- 
neer : 

Comprising  the  Grinding  and  Sharpening  of  Cutting  Tools,  Abia-.ve 
Processes,  Lapidary  Work,  Gem  and  Glass  Engraving,  Varnishing 
and  Lackering,  Apoa>-atus,  Materials  and  Processes  for  Grinding  and 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


7 


Polishing,  etc.    By  Oliver  Byrne.    Illustrated  by  185  wood  en- 
gravings.   8vo.        ........  $5.00 

9YRNE. — Pocket-Book  for  Railroad  and  Civil  Engineers: 

Containing  New,  Exact  and  Concise  Methods  for  Laying  out  Railroad 
Curves,  Switches,  Frog  Angles  and  Crossings;  the  Staking  out  of 
work;  Levelling;  the  Calculation  of  Cuttings;  Embankments;  Earth- 
work, etc.  By  Oliver  Byrne.  i8mo.,  full  bound,  pocket-book 
form  $1.50 

bYRNE. — Tne  Practical  Metal-Worker's  Assistant: 
Comprising  Metallurgic  Chemistry;  the  Ans  of  Working  all  Metals 
and  Alloys;  Forging  of  Iron  and  Steel;  Hardening  and  Tempering; 
Melling  and  Mixing;  Casting  and  Founding;  Works  in  Sheet  Metal; 
the  Processes  Dependent  on  the  Ductility  of  ihe  Metals;  Soldering; 
and  the  most  Improved  Processes  and  Tools  employed  by  Metal- 
workers. With  the  Application  of  the  Art  of  Electro- Metallurgy  to 
Manufacturing  Processes;  collected  from  Original  Sources,  and  Irom 
the  works  of  Holtzapffel,  Bergeron,  Leupold,  Piumier,  Napier, 
Scoffern,  Clay,  Fairbairn  and  others.  By  Oliver  Byrne.  A  new, 
revised  and  improved  edition,  to  which  is  added  an  Appendix,  con- 
taining The  Manufacture  of  Russian  Sheet-Iron.  By  John  Percy, 
M.  D.,  F.  R.  S.  The  Manufacture  of  Malleable  Iron  Castings,  and 
Improvements  in  Bessemer  Steel.  By  A.  A.  Fesquet,  Chemist  and 
Engineer.  With  over  Six  Hundred  Engravings,  Illustrating  every 
Branch  of  the  Subject.    8vo  #5.00 

B  iRNE. — The  Practical  Model  Calculator: 

For  ihe  Engineer,  Median. c,  Manufacturer  of  Engine  Work,  Navai 
Architect,  Miner  and  Millwright.  By  Oliver  Byrne.  8vo.,  nearly 
600  pages        .........       $ 3 .00 

CABINET  MAXER'S  ALBUM  OF  FURNITURE. 

Comprising  a  Collection  of  Designs  for  various  Styles  of  Furniture. 
Illustrated  by  Forty-eight  Large  and  Beautifully  Engraved  Plates. 
Oblong,  8vo   .  £1.50 

CALLINGHAM. — Sign  Writing  and  Glass  Embossing: 

A  Complete  Practical  Illustrated  Manual  of  the  Art.  By  James 
Callingham.    121110  $i-5° 

CAMPIN. — A  Practical  Treatise  on  Mechanical  Engineering: 
Comprising  Metallurgy,  Moulding,  Casting,  Forging,  Tools,  Work, 
shop  Machinery,  Mechanical  Manipulation,  Manufacture  of  Steam- 
Engines,  etc.  With  an  Appendix  on  the  Analysis  of  Iron  and  Iron 
Ores.  By  Francis  Camimn,  C.  E.  To  which  are  added,  Observations 
on  the  Construction  of  Steam  Boilers,  and  Remarks  upon  Furnaces 
used  for  Smoke  Prevention;  with  a  Chapter  on  Explosions.  By  R. 
Armstrong,  C.  E.,  and  John  Bourne.  Rules  for  Calculating  th« 
Change  Wheels  for  Screws  on  a  Turning  Lathe,  and  lor  a  Wheel* 
cutting  Machine.  By  J.  La  Nicca.  Management  of  Steel,  Includ- 
ing  Forging,  Hardening,  Tempering,  Annealing,  Shrinking  and 
Expansi  in  ;  and  the  Case-hardening  of  Iron.  By  G.  Edf.  8vo. 
Illustrated  with  twenty-nine  plates  and  100  wood  engraving*  $5.00 


8 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


CAREY. — A  Memoir  of  Henry  C.  Carey. 

By  Dr.  Wm.  Elder.   With  a  portrait.    8vo.,  cloth      .      .  75 

CAREY. — The  Works  of  Henry  C.  Carey: 

Harmony  of  Interests  :  Agricultural,  Manufacturing  and  Commer- 
cial.   8vo.    .       .  $1.25 

Manual  of  Social  Science.    Condensed  from  Carey's  "  Principles 
of  Social  Science."    By  Kate  McKEAN.  i  vol.  I2mo.     .  $2.00 
Miscellaneous  Works.    With  a  Portiait.    2  vols.  8vo.  $10.00 
Past,  Present  and  Future.    8vo.  .....  S2.50 

Principles  of  Social  Science.  3  volumes,  8vo.  .  .  S7.50 
The  Slave-Trade,  Domestic  and  Foreign;  Why  it  Exists,  and 
How  it  may  be  Extinguished  (1853).  8vo.  .  .  ,  $2.00 
The  Unity  of  Law:  As  Exhibited  in  the  Relations  of  Physical, 
Social,  Mental  and  Moral  Science  (1S72).    8vo.       .       .  $2.50 

CLARK. — Tramways,  their  Construction  and  Working: 

Embracing  a  Comprehensive  History  of  the  System.  With  an  ex- 
haustive analysis  of  the  various  modes  of  traction,  including  horse- 
power, steam,  heated  water  a.id  compressed  air;  a  description  of  the 
varieties  of  Rolling  stock,  and  ample  details  of  cost  and  working  ex- 
penses. By  D.  Kinnear  C'.ark.  Illustrated  by  over  200  wood 
engravings,  and  thirteen  folding  plates.      I  vol.    8vo.        .  $7.50 

COLBURN.— The  Locomotive  Engine  ; 

Including  a  Description  of  it-.  Structure,  Rules  for  Estimating  its 
Capabilities,  ami  Practical  Observations  on  its  Construction  and  Man- 
agement.   By  Zerah  Colburn.    Illustrated.    121110.       .  $1.00 

COLLENS.— The  Eden  of  Labor ;  or,  the  Christian  Utopia. 
By  T.  Wharton  Collens,  author  of  "  Human ics,"  "The  History 
of  Charity,"  etc.    I2mo.     Paper  cover,  $  1 .00 ;  Cloth        .  $1.25 

COO  LEY. — A  Complete  Practical  Treatise  on  Perfumery: 

Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet  Articles. 
With  a  Comprehensive  Collection  of  Formulae.  By  Arnold  J. 
Coolky.  i2mo  $1.50 

COOPER.— A  Treatise  on  the  use  of  Belting  for  the  Trans- 
mission of  Power. 
With  numerous  illustrations  of  approved  and  actual  methods  of  ar- 
ranging Main  Driving  and  Quarter  Twist  Belts,  and  of  Relt  Fasten 
ings.  Examples  and  Rules  in  great  number  for  exhibiting  ar>d  cal- 
culating the  size  and  driving  power  of  Belts.  Plain,  Particular  and 
Practical  Directions  for  the  Treatment,  Care  and  Man  igement  or 
Belts.  Descriptions  of  many  varieties  of  Beltings,  together  witn 
chapters  on  the  Transmission  of  Power  by  Ropes;  by  Iron  and 
Wood  Frictional  Gearing;  <>n  the  Strength  of  Belting  Leather;  and 
011  the  Experimental  Investigations  of  Morin,  Briggs,  and  uthers.  By 
John  H.  Cooper,  M.  E.  8vo  $3-50 

CRAIK. — The  Practical  American  Millwright  and  M;Uer. 
By  David  Craik,  Millwright.    Illustrated  by  numerous  wood  en 
fiT'avings  and  two  folding  plates.    8vo.       ....  #3-50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


CROSS. — The  Cotton  Yarn  Spinner: 

Showing  how  liie  Preparation  should  be  arranged  for  Different 
Counts  of  Yarns  by  a  System  more  uniform  than  has  hitherto  been 
practiced;  by  having  a  Standard  Schedule  from  which  we  make  all 
our  Changes.    By  Richard  Cross.    122  pp.    121110.       .  75 

CRISTIANI. —  A  Tech  ical  Treatise  on  Soap  and  Candles: 

With  a  Glance  at  die  Industry  of  Eats  and  Oils.  By  R.  S.  Cris- 
TIANI,  Chemist.  Author  of"  Perfumery  and  Kindred  Arts."  Illus- 
trated by  176  engravings.    5S1  pages,  8vo. 

COURTNEY. — The  Boiler  Maker's  Assistant  in  Drawing, 
Templating,  and  Calculating  Boiler  Work  and  Tank 
Work,  etc. 

Revised  by  D.  K  CLARK.  102  ills.  Fifth  edition.  .  .  80 
COURTNEY.— The  Boiler  Maker's  Ready  Reckoner: 

With  Examples  of  Practical  Geometry  and  Templating.  Revised  by 
D.  K.  Clark,  C.  E.    37  illustrations.    Fifth  edition.      •  $1.60 

DAVIDSON. — A  Practical  Manual  of  House  Painting,  Grain- 
ing, Marbling,  and  Sign- Writing  : 
Containing  full  information  on  the  processes  of  House  Painting  in 
Oil  and  Distemper,  the  Formation  of  Letters  and  Practice  of  Sign- 
Writing,  the  Principles  of  Decorative  Art,  a  Course  of  Elementary 
Drawing  for  House  Painters,  Writers,  etc.,  anil  a  Collection  of  Useful 
Receipts.  With  nine  colored  illustrations  of  Woods  and  Marbles, 
and  numerous  wood  engravings.    By  Ellis  A.  Davidson,    i  21110. 

$2.00 

DAVIES— A  Treatise  on  Earthy  and  Other   Minerals  and 

Mining: 

By  I>.  C  DAVIES,  F.  G.  S.,  Mining  Engineer,  etc.  Illustrated  by 
76  Engravings.    121110.       .       .       .       .      .       .       .   $5  00 

DAVIES.  —  A  Treatise  on  Met  lliferous  Minerals  and  W  ining: 

Bv  I)  C.  Daviks,  F.  G.  S.  Mining  Engineer,  Examiner  of  Mines, 
Quarries  and  Collieries.  Illustrated  by  148  engravings  of  Geological 
Formations,  Mining  Operations  and  Machinery,  drawn  from  the 
practice  of  all  parts  of  the  vvorl  I.  Fifth  Edition,  thoroughly  Revised 
and  much  Enlarged  by  his  son,  E.  Henry  Davies.  i2ino ,  524 
pages       .......  ?5  00 

DAVIES.— A  Treatise  on  Slate  and  Slate  Quarrying: 

Scientific,  Practical  and  Commercial.    By  I)   C.  Davds.  F.  G  S, 
Mining  Engineer,  etc.    With  numerous  illustrations  and  folding 
plates.    ;2mo         .       .       .       .       .       .       .       .  $200 

DAVIS. — A  Practical  Treatise  on  the  Manufacture  of  Brick, 
Tiles  and  Terra-Cotta  : 
Including  Stiff  Cln\  Dry  Clay,  Hand  Made.  Pressed  or  Front,  and 
Roadway  Paving  Brick,  Enamelled  Brick,  with  Glazes  and  Colors, 
Fire  Brick  and  Blocks,  Silica  Brick,  Carbon  Brick,  Glass  Pots,  Re- 


IO        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


torts,  Architectural  Terra-Cott.i,  Sewer  Pipe,  Drain  Tile,  Glazed  and 
Unglazed  Roofing  Tile,  Art  Tile,  Mosaics,  and  Imitation  of  Intarsia 
or  Inlaid  Surfaces.  Compulsing  every  product  of  Clay  employed  in 
Architecture,  Engineering,  and  the  Blast  Furnace.  With  a  Detailed 
Description  of  the  Different  Clays  employed,  the  Most  Modern 
Machinery,  Tools,  and  Kilns  used,  and  the  Processes  for  Handling, 
Disintegrating,  Tempering,  and  Moulding  the  Clay  into  Shape,  Dry- 
ing, Setting,  and  Burning.  By  Charles  Thomas  Davis.  Third  Edi- 
tion. Revised  and  in  great  part  rewritten.  Illustrated  by  261 
engravings.    662  pages    .......       $5  00 

DAVIS. — A  Treatise  on  Steam-Boiler  Incrustation  and  Meth- 
ods for  Preventing  Corrosion  and  the  Formation  of  Scale: 
By  Charles  T.  Davis.    Illustrated  by  65  engravings.    8vo.  $2.00 

DAVIS. — The  Manufacture  of  Paper: 

Being  a  Description  of  the  various  Processes  for  the  Fabrication, 
Coloring  and  Finishing  of  every  kind  of  Paper,  Including  the  Dif- 
ferent Raw  Materials  and  the  Methods  for  Determining  their  Values, 
the  Tools,  Machines  and  Practical  Details  connected  with  an  intelli- 
gent and  a  profitable  prosecution  of  the  art,  with  special  reference  to 
the  best  American  Practice.  To  which  are  added  a  History  of  Pa- 
per, complete  Lists  of  Paper- Making  Materials,  List  of  American 
Machines,  Tools  and  Processes  used  in  treating  the  Raw  Materials, 
and  in  Making,  Coloring  and  Finishing  Paper.  By  Charles  T. 
Davis.    Illustrated  by  156  engravings.    608  pages,  8vo.  $6.00 

DAVIS. — The  Manufacture  of  Leather: 

Being  a  Description  of  all  the  Processes  for  the  Tanning  and  Tawing 
with  Bark,  Extracts,  Chrome  and  all  Modern  Tannages  in  General 
Use.  and  the  Currying,  Finishing  and  Dyeing  of  Every  Kind  of  Leather; 
Including  the  Various  Raw  Materials,  the  Tools,  Machines,  and  all 
Details  of  Importance  Connected  with  an  Intelligent  and  Profitable 
Prosecution  of  the  Art,  with  Special  Reference  to  the  Best  American 
Practice.  To  which  are  added  Lists  of  American  Patents  ( 1884-1897) 
for  Materials,  Processes,  Tools  and  Machines  for  Tanning,  Currying, 
etc.  By  Charles  Thomas  Davis.  Second  Edition,  Revised,  and 
in  great  part  Rewritten.  Illustrated  by  147  engravings  and  14  Sam- 
ples ol  Quebracho  Tanned  and  Aniline  Dyed  Leathers.  8vo,  cloth, 
712  pages.    Price    .   $7  5° 

DAWIDOWSKY — BR  AN  NT.— A  Practical  Treatise  on  the 
Raw  Materials  and  Fabrication  of  Glue,  Gelatine,  Gelatine 
Veneers  and  Foils,  Isinglass,  Cements,  Pastes,  Mucilages, 
etc. : 

Kased  upon  Actual  Experience.  By  F.  Dawidowsky,  Technical 
Chemist.  Translated  from  the  German,  with  extensive  additions, 
including  a  description  of  the  most  Recent  American  Processes,  by 
William  T.  Brannt,  Graduate  of  the  Royal  Agricultural  College 
of  Eldena,  Prussia.  35  Engravings.  l2mo.  .  .  .  $2.50 
DE  GRAFF.— The  Geometrical  Stair-Builders'  Guide: 

being  a  Plain  Practical  System  of  Hand-Railing,  embracing  all  its 
necessary  Details,  and  Geometrically  Illustrated  by  twenty-two  Steel 
Engravings;  together  with  the  use  of  the  most  approved  principle* 
of  Practical  Geometry.    By  Simon  De  Graff,  Architect.  +to. 

#2.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  II 


DE  KONINCK — DIETZ. — A  Practical  Manual  of  Chemical 
Analysis  and  Assaying : 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to  Cast  Iron, 
Wrought  Iron,  and  Steel,  as  found  in  Commerce.  By  L.  L.  De 
KonincK,  Dr.  Sc.,  and  E.  Dif.tz,  Engineer.  Edited  with  Notes,  by 
Robert  Mallet,  F.  R.  S.,  F.  S.  G.,  M.  I.  C.  E.,  etc.  American 
Edition,  Edited  with  Notes  and  an  Appendix  on  Iron  Ores,  by  A.  A. 
FESQUET,  Chemist  and  Engineer.    121110.         .       .       .  $1.50 

L  UNCAN.—  Practical  Surveyor's  Guide: 
Containing  the  necessary  information  to  make  any  person  of  corn* 
mon  capacity,  a  finished  land  surveyor  without  the  aid  of  a  teacher 
By  Andrew  Duncan.    Revised.  72  engravings,  714  pp.  i2mo.  $1.50 

DUPLAIS. — A  Treatise  on  the  Manufacture  and  Distillation 
of  Alcoholic  Liquors : 
Comprising  Accurate  and  Complete  Details  in  Regard  to  Alcohol 
from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes,  Sorghum,  Aspho 
del,  Fi uits,  etc. ;  with  the  Distillation  and  Rectification  of  Brandy, 
Whiskey,  Rum,  Gin,  Swiss  Absinthe,  etc.,  the  Preparation  of  Aro- 
matic Waters,  Volatile  Oils  or  Essences,  Sugars,  Syrups,  Aromatic 
Tinctures,  Liqueurs,  Cordial  Wines,  Effervescing  Wines,  etc.,  the 
Ageing  of  Brandy  and  the  improvement  of  Spirits,  with  Copiow 
Directions  and  Tables  for  Testing  and  Reducing  Spirituous  Liquors, 
etc  j  etc  Translated  and  Edited  from  the  French  of  MM.  Dui'I.AIS, 
By  M.  McKennie,  M.  D.    Illustrated     743  pp.    8vo.  J515.00 

DYER  AND  COLOR- MAKER'S  COMPANION  : 

Containing  upwards  of  two  hundred  Receipts  for  making  Colors,  on 
the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  evistence  ;  with  the  Scouring  Process,  and  plain  Directions  for 
Preparing.  Washing-ofF,  and  Finishing  the  Goods.     I2mo.        $1  00 

EIDHERR.— The  Techno-Chemical  Guide  to  Distillation: 
A  Hand-Book  for  the  Manufacture  of  Alcohol  and  Alcoholic  Liquors, 
including  the  Preparation  of  Malt  and  Compressed  Yeast.  Edited 
from  the  German  of  Ed.  Eidherr.    Fully  illustrated.   (In  preparation.) 

EDWARDS. — A  Catechism  of  the  Marine  Steam-Engine, 
For  the  use  of  Engineers.  Firemen,  and  Mechanics.  A  Practical 
Work  for  Practical  Men.  Piy  EMORY  Edwards,  Mechanical  Engi- 
neer. Illustrated  by  sixty  three  Engiavings.  including  examples  of 
the  most  modern  Engines.  Third  edition,  thoroughly  revised,  with 
much  additional  matter.     l2mo.  414  pages       .        .        .        $2  00 

EDWARDS. — Modern  American  Locomotive  Engines, 
Thc!r  Design,  Construction  and  Management.    By  Emory  EDWARD&, 
Illustrated  l2tno  $2.00 

EDWARDS.— The  American  Steam  Engineer: 

Theoretical  and  Practical,  with  examples  of  the  latest  and  most  ap- 
proved American  practice  in  the  design  and  construction  of  Steam 
Er.gines  and  Boilers.  For  the  use  of  engineers,  machinists,  boiler- 
pn^kers,  and  engineering  students.  By  Emory  Edwards.  Fully 
illustrated,        419  pages.    l2mo.  •  $2.50 


12        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


EDWARDS. — Modern  American  Marine  Engines,  Boilers,  an< 
Screw  Propellers, 

Their  Design  and  Construction.    Showing  the  Present  Prnaice  ot 
the  mot  Eminent  Engineers  and  Marine  Engine  Buildeis  in  the 
United  States.  Illustrated  by  30  large  and  elaborate  plates.  410.  $5.00 
(EDWARDS. — The  Practical  Steam  Enginesr's  Guide 

In  the  Design,  Construction,  and  Management  of  American  Stationary, 
Portable,  and  Steam  Fire- Engines,  Steam  Pumps,  Boilers,  injectors, 
Governors,  Indicators,  Pistons  and  Rings,  Safety  Valves  and  Steam 
Gauges.  For  the  use  of  Engineers,  Firemen,  and  Steam  Ujers.  By 
Emory  Edwards.  Illustrated  by  119  engravings.  A20  pages. 
121110.     ..........       $2  50 

EISSLER. — The  Metallurgy  of  Gold: 
A  Practical  Treatise:  on  the  Metallurgical  Treatment  of  Gold-Bear- 
ing  Ores,  including  the  Processes  of  Concentration  ami  Clilorination, 
and  the  Assaying,  Melting,  and  Refining  of  Gold.    By  M.  Eissler. 
With  132  Illustrations.     121110.        .....  $5.00 

EISSLER.— The  Metallurgy  of  Silver  : 

A  Practical  Treatise  on  the  Amalgamation,  Roasting,  and  Lixiviation 
of  Silver  Ores,  including  the  Assaying,  Melting,  and  Refining  of 


Silver   Bullion.    By    M.    ElSSLER.    124   Illustrati  011s.     33^  PP* 

I2mo  $4 .25 

ELDER. — Conversations  on  the  Principal  Subjects  of  Political 
Economy. 

By  Dr.  William  Elder.    8vo  $2 .50 

ELDER.— Questions  of  the  Day, 

Economic  and  Social.  By  Dr.  William  Elder.  8vo.  .  $3. 00 
SRNI. — Mineralogy  Simplified. 


Easy  Methods  of  Determining  and  Classifying  Minerals,  including 
Ores,  by  menns  of  the  Blow]  ipe,  and  by  Humid  Chemical  Analysis, 
based  on  Professor  von  K<  bell's  Tables  for  the  Determination  of 
Minerals,  with  an  Introduction  to  Modern  Chemistry.     By  Hf.NRY 
Erni,  A.M.,  M.D.,  Professor  of  Chemistry.  Second  Edition,  rewritten, 
enlarged  and  improved.  I2mo.  .... 
FAIRBAIRN. — The  Principles  of  Mechanism  and  Machinery 
of  Transmission  ■ 
Comprising  the   Principles  of  Mechanism,  Wheels,  and  Pullevs, 
Strength  and  Proportions  of  Shafts,  Coupling  of  Shatts,  and  Engng. 
ing  and  Disengaging  Gear.    By  SlB  William  Fairuairn,  Bait 
C.  E.    Beautifully  tllusttated  by  over  150  wood  cuts.     In  one 
volume.  l2tno  $2.00 
FLEMING. — Narrow  Gauge  Railways  in  America. 

A  Sketch  of  their  Rise,  Progress,  and  Success.  Valuable  Statistics 
as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives,  Cars,  e'c.  By 

Howard  Fleming.    Illustrated,  8vo  $1  00 

FORSYTH. — Book  of  Designs  for  Headstones,  Mural,  and 
othtr  Monuments : 
Containing  78  Designs.    By  James  Forsyth.  With  an  Introduction 
by  Charles  BguteLL,  M.  A.    4  to.,  cloth     .       .  $3-5<> 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  13 


FRANKEL— HUTTER. — A  Practical  Treatise  on  the  Manu« 
facture  of  Starch,  Glucose,  Starch-Sugar,  and  Dextrine: 

Based  on  the  German  of  Lauislaus  Von  Wagner,  I'rofessor  in  the 
Royal  Technical  High  School,  Budapest,  Hungary,  and  other 
authorities.  By  Julius  Fkankf.l,  Graduate  of  the  Polytechnic 
School  of  Hanover.  Edited  by  Robert  H utter,  Chemist,  Practical 
Manufacturer  of  Starch-Sugar.  Illustrated  by  58  engravings,  cover- 
ing every  branch  of  the  subject,  including  examples  of  the  most 
Recent  and  Best  American  Machinery.    8vo.,  344  pp.     .       $3  50 

GARDNER. — The  Painters  Encyclopaedia: 
Containing  Definitions  of  all  Important  Words  in  the  Art  of  Plain 
and  Artistic  Painting,  with  Details  of  Practice  in  Coach,  Carriage, 
Railway  Car,  House,  Sign,  and  Ornamental  Painting,  including 
Graining,  Marbling,  Staining,  Varnishing,  Polishing,  Lettering, 
Stenciling,  Gilding,  Bronzing,  etc.  By  Franklin  B.  Gardner. 
158  Illustrations.    l2mo.    427  pp.  .....  #2.00 

GARDNER.— Everybody's  Paint  Book: 

A  Complete  Guide  to  the  Art  of  Outdoor  and  Indoor  Painting.  38 
illustrations      121110,  183  pp.    ......  $1.00 

GEE. — The  Jeweller's  Assistant  in  the  Art  of  Working  in 
Gold: 

A  Practical  Treatise  foi  Masters  and  Workmen.     121110.     .      $3  00 

GEE.— The  Goldsmith's  Handbook: 

Containing  full  instructions  lor  the  Alloying  and  Working  of  Gold, 
including  the  Art  of  Alloying,  Melting,  Reducing,  Coloring,  Col- 
lecting,  and  Refining;  the  Processes  of  Manipulation,  Recovery  of 
Waste ;  Chemical  and  Physical  Properties  of  Gold ;  with  a  New 
System  of  ?>lixing  its  Alloys;  Solders,  Enamels,  and  other  Useful 
Rules  and  Recipes.    By  George  E.  Gee.    i2mo.  „       .  $1.25 

GEE.— The  Silversmith's  Handbook  : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Silver, 
including  the  different  modes  of  Refinin-  and  Melting  the  Metal ;  its 
Solders;  the  Preparation  of  Imitation  Alloys;  Methods  of  Manipula- 
tion ;  Prevention  of  Waste  ;  Instructions  for  Improving  and  Finishing 
the  Surface  of  the  Work  ;  together  with  other  Useful  Information  and 
Memoranda.    By  George  E.  Gee.    Illustrated.    121110.       Si. 25 

GOTHIC  ALBUM  FOR  CABINET-MAKERS: 

Designs  for  Gothic  Furniture.    Twenty-three  plates.    Oblong  $1.50 

3RANT. — A  Handbook  on  the  Teeth  of  Gears  : 

Their  Curves,  Properties,  and  Practical  Construction.  By  Georgk 
B.  Grant.    Illustrated.    Third  Edition,  enlarged.    8vo.        Si  00 

3REENWOOD. — Steel  and  Iron: 
Comprising  the  Practice  and  Theory  of  the  Several  Methods  Pur- 
sued in  their  Manufacture,  and  of  their  Treatment  in  the  Rolling- 
Mills,  the  Forge,  and  the  Foundry.    By  William  Henry  Green- 
wood, F.  C.  S.    With  97  Diagrams,  536  pages.    121110.  S'-75 


14      HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


GREGORY. — Mathematics  for  Practical  Men  : 

Adapied  to  the  Pursuits  of  Surveyors,  Architects,  Mechanics,  and 
Civil  Engineers.    By  Olinthus  Gregory.    8vo.,  plates      $3  00 
GRISWOLD. — Railroad  Engineer's  Pocket  Companion  for  tru 
Field : 

Comprising  Rules  for  Calculating  Deflection  Distances  and  Angles 
Tangential  Distances  and  Angles,  and  all  Necessary  Tables  for  I  in 
gmeers;  also  the  Art  of  Levelling  from  Preliminary  Survey  to  :nc 
Construction  of  Railroads,  intended  Expressly  for  the  Young  Kn- 
gineer,  together  with  Numerous  Valuable  Rules  and  Examples.  B\ 
W.  GR  IS  WOLD.     I2mo.,  tucks  $150 

GRUNER. — Studies  of  Blast  Furnace  Phenomena: 

By  M.  L.  Gruner,  President  of  the  General  Council  of  Mines  o^ 
France,  and  lately  Professor  of  Metallurgy  at  the  Ecole  des  Mines 
Translated,  with  the  author's  sanction,  with  an  appendix,  by  L.  IV 
B.  Gordon,  F.  R.  S.  E.,  F.  G.  S.    8vo.  .       .       .  52.50 

Hand-Book  of  Useful  Tables  for  the  Lumberman,  Farmer  and 
Mechanic : 

Containing  Accurate  Tables  of  Logs  Reduced  to  Inch  Board  Meas- 
ure, Plank,  Scantling  and  Timber  Measure;  Wages  and  Rent,  by 
Week  or  Month;  Capacity  of  Granaries,  Bins  and  Cisterns;  Land 
Measure,  Interest  Tables,  with  Directions  for  Finding  the  Interest  on 
any  sum  at  4,  5,  6,  7  and  8  per  cent.,  and  many  other  Useful  Tables. 
32  mo.,  boards.    186  pages     ......  .25 

HASERICK. — The  Secrets  of  the  Art  of  Dyeing  Wool,  Cotton, 
and  Linen, 

Including  Bleaching  nn>i  Coloring  Wool  and  Cotton  Hosiery  and 
Random  Yarns.  A  Treatise  based  on  Economy  and  Practice.  By 
E.  C.  Haserick.    Illustrated  by  323  Dyed  Patterns  of  the  Yarni 


or  Fabrics.  8vo.       ........  $7-5° 

HATS  AND  FELTING: 

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HERMANN. — Painting  on  Glass  and  Porcelain,  and  Enamel 
Painting : 

A  Complete  Introduction  to  the  Preparation  of  all  the  Colors  and 
Fluxes  Used  for  Painting  on  Glass,  Porcelain,  Enamel,  Faience  and 
Stoneware,  the  Color  Pastes  and  Colored  Glasses,  together  with  a 
Minute  Description  ot  the  Firing  ot  Colors  and  Enamels,  on  the 
Basis  of  Personal  Practical  Experience  of  the  Art  up  to  Date.  18 
illustrations.    Second  edition.  .....  $4-00 

HAUPT. — Street  Railway  Motors: 

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HURST. — Lubricating  Oils,  Fats  and  Greases: 

Their  Origin,  Preparation,  Properties,  Uses  and  Analysis.  65  illus- 
trations.   8vo.         .       .   S4.00 

HURST.— Soaps: 

A  Practical  Manual  of  the  Manufacture  of  Domestic,  Toilet  and 
Other  Soaps.    66  illustrations.    8vo.       ....  #5.00 

HUGHES. — American  Miller  and  Millwright's  Assistant: 
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HULME. — Worked  Examination  Questions  in  Plane  Geomet  - 
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graph Departments;  Royal  Marine  Light  Infantry;  the  Oxford  and 
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KEENE.-A  Hand-Book  of  Practical  Gauging: 

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KELLOGG. — A  New  Monetary  System  : 
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Property,  and  of  Protecting  the  Public  from  Financial  Revulsions. 
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KEMLO. — Watch-Repairer's  Hand-Book  : 
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Putting  Together,  and  Thoroughly  Cleaning  the  English  Lever  and 
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i6 


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KENTISH.— A  Treatise  on  a  Box  of  Instruments, 

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rithms,  including  Practical  Geometry,  Surveying,  Measuring  of  Tim- 
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Kentish.    In  one  volume.    i2mo.  ....  $i.oo 

KERL.— The  Assayer's  Manual: 

An  Abridged  Treatise  on  the  Docimastic  Examination  of  Ores,  and 
Furnace  and  other  Artificial  Products.  By  Bruno  Kerl,  Professor 
in  the  Roval  School  of  Mines.  Translated  from  the  German  by 
William  T.  Brannt.  Second  American  edition,  edited  with  Ex- 
tensive Additions  by  F.  Lynwood  Garrison,  Member  of  the 
American  Institute  of  Mining  Engineers,  etc.  Illustrated  by  87  en- 
gravings.   8vo.  .   

KICK. — Flour  Manufacture. 

A  Treatise  on  Milling  Science  and  Practice.  By  Frederick  Kick 
Imperial  Regierungsrath,  Professor  of  Mechanical  Technology  in  thi 
imperial  German  Polytechnic  Institute,  Prague.  Translated  from 
the  second  enlarged  and  revised  edition  with  supplement  by  H.  H 
P.  Powles,  Assoc.  Memb  Institution  of  Civil  Engineers.  Illustrated 
with  28  Pla'ps,  and  167  VVood-cuts.    367  pages.    8vo.     .  #10.00 

KINGZETT. — The  History,  Products,  and  Processes  of  the 
Alkali  Trade  : 

Including  the  most  Recent  Improvements.  By  Charles  Thomas 
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KIRK. — The  Cupola  Furnace: 

A  Practical  Treatise  on  the  Construction  and  Management  of  Foundry 
Cupolas.  By  Edward  Kirk,  Practical  Moulder  and  Melter,  Con- 
sulting Expert  in  Melting.  Author  of  "  The  Founding  of  Metals." 
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LANDRIN. — A  Treatise  on  Steel : 

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and  Use.  By  M.  H.  C.  Landrin,  Jr.  From  the  French,  by  A.  A. 
Fesquet.    lamo  $2-50 

LAN  GBEIN. — A  Complete  Treatise  on  the  Electro-Deposi. 
tion  of  Metals : 
Comprising  Electro-Plating  and  Galvanoplastic  Operations,  the  De- 
position of  Metals  by  the  Contact  ar.d  Immersion  Processes,  the  Color- 
ing of  Metals,  the  Methods  of  Grinding  and  Polishing,  as  well  as 
Descriptions  of  the  Electric  Elements  Dynamo-Electric  Machines, 
Thermo- Piles  and  of  the  Materials  and  Processes  used  in  Every  De- 
partment of  the  Art.  From  the  German  of  Dr.  George  Langbein, 
with  additions  by  Wm.  T.  Brannt.  Third  Edition,  thoroughly  re 
vised  and  much  enlarged.    150  Engravings.    528  pages.    8vo.  $4.00 

LARDNER. — The  Steam-Engine  : 

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LEHNER. — The  Manufacture  of  Ink: 

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LARKIN. — The  Practical  Brass  and  Iron  Founder's  Guide: 

A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals  and 
their  Alloys,  etc.;  to  which  are  added  Recent  Improvements  in  the 
Manufacture  of  Iron,  Steel  by  the  Bessemer  Process,  etc.,  etc.  By 
JAMES  Larkin,  late  Conductor  of  the  Brass  Foundry  Department  iu 
Reany,  Neafie  &  Co.'s  Penn  Works,  Philadelphia.  New  edition, 
revised,  with  extensive  additions.     l2mo.  .        .        .  $2.50 

LEROUX. — A  Practical  Treatise  on  the  Manufacture  of 
Worsteds  and  Carded  Yarns: 
Comprising  Practical  Mechanics,  with  Rules  and  Calculations  applied 
to  Spinning;  Sorting,  Cleaning,  and  Scouring  Wools;  the  English 
and  French  Methods  of  Combing,  Drawing,  and  Spinning  Worsteds, 
and  Manufacturing  Carded  Yarns.  Translated  from  the  French  of 
Charles  Leroux,  Mechanical  Engineer  and  Superintendent  of  a 
Spinning  Mill,  by  Horatio  Paine,  M.  D.,  and  A.  A.  Fesquet, 
Chemist  and  Engineer.  Illustrated  by  twelve  large  Plates.  To  which 
is  added  an  Appendix,  containing  Extracts  from  the  Reports  of  the 
International  Jury,  and  of  the  Artisans  selected  by  the  Committee 
appointed  by  the  Council  of  the  Society  of  Arts,  London,  on  Woolen 
and  Worsted  Machinery  and  Fabric^,  as  exhibited  in  the  Paris  Uni. 
versai  Exposition,  1867.   8vo.  .       .       .       .       ,  $5.00 

LEFFEL. — The  Construction  of  Mill-Dams  : 

Comprising  also  the  Bulding  of  Race  and  Reservoir  Embankments 
and  Mead-Gates,  the  Measurement  of  Streams,  Gauging  of  Water 
Supply,  etc.  By  James  Lkffel  &  Co.  Illustrated  by  58  engravings. 
8vo.  $2,50 

LESLIE.— Complete  Cookery: 

Directions  for  Cookery  in  its  Various  Branches.  By  Miss  Leslie. 
Sixtieth  thoasand.  Thoroughly  revised,  with  the  addition  of  New 
Receipts.     i2mo.     ........  $1-5° 

LE  VAN. — The  Steam  Engine  and  the  Indicator: 

Their  Origin  and  Progressive  Development;  including  the  Most 
Recent  Examples  of  Steam  and  Gas  Motors,  together  with  the  Indi- 
cator, its  Principles,  its  Utility,  and  its  Application.  By  William 
Barnkt  Le  Van.  Illustrated  by  205  Engravings,  chiefly  of  Indi- 
cator-Cards.   469  pp.    8vo.     .       .       .       .  .  $4.00 

LIEBER. — Assayer's  Guide  : 
Or,  Practical  Directions  to  Assayers,  Miners,  and  Smelters,  for  the 
Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for  the  Ores  of  al! 
the  principal  Metals,  of  Gold  and  Silver  Coins  and  Alloys,  and  of 
Coal,  etc.    By  Oscar  M.  LlEBER.     Revised.  283  pp.  i2nio.  S1.50 

Cockwood's  Dictionary  of  Terms  :  , 
Used  in  the  Practice  of  Mechanical  Engineering,  embracing  those] 
Current  in  the  Drawing  Office,  Pattern  Shop,  Foundry,  Fitting,  Turn-. 
!ng,  Smith's  and  Boiler  Shops,  etc.,  etc.,  comprising  upwards  of  Six', 
Thousand  IVfinitions.  Edited  by  a  Foreman  Pattern  Maker,  author' 
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LUKIN. —  The  Lathe  and  Its  Uses: 

Or  Instruction  in  the  Art  of  Turning  Wood  and  Metal.  Including 
a  Description  of  tlie  Most  Modern  Appliances  for  the  Ornamentation 
of  Plane  and  Curved  Surfaces,  an  Entirely  Novel  Form  of  Lathe 
for  Eccentric  ami  Rose-Engine  Turning;  A  Lathe  and  Planing 
Machine  Combined;  and  Other  Valuable  Matter  Relating  to  the 
Art.  Illustrated  by  462  engravings.  Seventh  edition.  315  pages. 
8vo.        .       .  #4.25 

MAIN  and  BROWN. — Questions  on  Subjects  Connected  will- 
the  Marine  Steam-Engine : 

And  Examination  Paper-.;  with  Hints  for  their  Solution.  By 
Thomas  f.  Main,  Professor  of  Mathematics,  Royal  Naval  College, 
and  Thomas  Brown,  Chief  Engineer,  R.  N.    121110.,  cloth  .  #1.00 

MAIN  and  BROWN. — The  Indicator  and  Dynamometer: 
With  their  Practical  Applications  to  the  Steani-Engine.    By  THOMAS 
J.  Main,  M.  A.  F.  R.,  Ass't  S.  Professor  Royal  Naval  College, 
Portsmoulh,  and  Thomas  Brown,  Assoc.  Inst.  C.  E.,  Chief  Engineei 
R.  N.,  attached  to  ihe  R.  N.  College.    Illustrated.    8vo.  . 

MAIN  and  BROWN.— The  Marine  Steam-Engine. 

By  Thomas  J.  Main,  F.  R.  Ass't  S.  Mathematical  Professor  at  the 
Royal  Naval  College,  Portsmouth,  and  THOMAS  BROWN,  Assoc. 
Inst.  C.  E..  Chief  Engineer  R.  N.  Attached  to  the  Royal  Nava! 
College.    With  numerous  illustrations.  8vo. 

MAKINS. — A  Manual  of  Metallurgy: 

By  George  Hogarth  Makins.  100  engravings.  Second  edition 
rewritten  and  much  enlarged.    i2mo.,  592  pages     .       .       $3  00 

MARTIN.— Screw-Cutting  Tables,  for  the  Use  of  Mechanica* 

Engineers  : 

Showing  ihe  Proper  Arrangement  of  Wheels  for  Cutting  the  Threads 
of  Screws  .of  any  Required  Pitch;  with  a  Table  for  Making  the  Uni- 
versal Gas-Pipe  Thread  and  Taps.  By  W.  A.  Martin,  Engineer. 
8vo.   .50 

MCHELL.- Mine  Drainage: 
Being  a  Compleie  and  Practical  Treatise  on  Direct-Acting  Under- 
ground Steam  Pumping  Machinery.  With  a  Description  of  a  large 
number  of  the  best  known  Engines,  their  General  Utility  and  the 
Special  Sphere  of  their  Action,  the  Mode  of  their  Application,  and 
their  Merits  compared  with  other  Pumping  Machinery.  By  Stephen 
MlCHELL.    Illustrated  by  137  engravings.    8vo.,  277  pages  .  $6.00 

IVOLESWORTH.— Pocket-Book  of   Useful    Formulae  and 
Memoranda  for  Civil  and  Mechanical  Engineers. 
Bv  Guilford  L.  Molesworth,  Member  of  the  Institution  of  Civil 
Engineers,  Chief  Resident  Engineer  of  the  Ceylon  Railway.  Full- 
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MOORE.— The  Universal  Assistant  and  the  Complete  Me- 
chanic : 

Containing  over  one  million  Industrial  Facts,  Calculations,  ReceiptSi 
Processes,  Trades  Secrets,  Rules,  Business  Forms,  Legal  Items,  Etc., 
in  every  occupation,  from  the  Household  to  the  Manufactory.  By 
R.  Moore.     Illustrated  by  500  Engravings.     I2mo.         .        $2. 50 

MORRIS. — Easy  Rules  for  the  Measurement  of  Earthworks: 
By  means  of  the  Prismoidal  Formula.  Illustrated  with  Numerout 
Wood-Cuts,  Problems,  and  Examples,  and  concluded  by  an  Exten- 
sive Table  for  finding  the  Solidity  in  cubic  yards  from  Mean  Areas. 
The  whole  being  adapted  for  convenient  use  by  Engineers,  Surveyors, 
Contractors,  and  others  needing  Correct  Measurements  of  Earthwork. 
By  Elwood  Morris,  C.  E.    8vo  51.5c 

MAUCHLINE. — The  Mine  Foreman's  Hand-Book 

Of  Practical  and  Theoretical  Information  on  the  Opening,  Venti- 
lating, and  Working  of  Collieries.  Questions  and  Answers  on  Prac- 
tical and  Theoretical  Coal  Mining.  Designed  to  Assist  Students  and 
Others  in  Parsing  Examinations  for  Mine  Foremanships.  By 
Robert  Mauchune,  Ex-Inspector  of  Mines.  A  New,  Revised  and 
Enlarged  Edition.  Illustrated  by  114  engrarings.  8vo.  337 
pages  $375 

NAPIER. — A  System  of  Chemistry  Applied  to  Dyeing. 

By  James  Napier,  F.  C.  S.  A  New  anil  Thoroughly  Revised  Edi- 
tion. Completely  brought  up  to  the  present  state  of  the  Science, 
including  the  Chemistry  of  Coal  Tar  Colors,  by  A.  A.  FESQUET, 
Chemist  and  Engineer.  With  an  Appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  Illus 
trated.  8vo.  422  pages      .......  $3-°° 

NEVILLE.— Hydraulic  Tables,  Coefficients,  and  Formulfe,  foi 
finding  the  Discharge  of  Water  from  Orifices,  Notches, 
Weirs,  Pipes,  and  Rivers: 
Third  Edition,  with  Additions,  consisting  of  New  Formula?  for  the 
Discharge  from  Tidal  and  Flood  Sluices  and  Siphons;  general  infor- 
mation on  Rainfall,  Catchment-Basins,  Drainage,  Sewerage,  Wa'.ei 
Supply  for  Towns  and  Mill  Power.  Bv  Tohn  Nevillk,  C.  E.  M  R 
I.  A.;  Fellow  of  the  Royal  Geological  Society  of  Ireland.  Thick, 
I2ino   $5-50 

NEWBERY.— Gleanings    from    Ornamental    Art  of  every 
style : 

Drawn  from  Examples  in  the  British,  South  Kensington,  Indian, 
Crysial  Palace,  and  other  Museums,  the  Exhibitions  of  1851  and 
I862,  and  the  best  English  and  Foreign  works.  In  a  series  of  100 
exquisitely  drawn  Plates,  containing  many  hundred  examples.  By 

Robert  Newbery.  410.  

NICHOLLS.  —The  Theoretical  and  Practical  Boiler-Maker  and 
Engineer's  Reference  Book: 
Containing  a  variety  of  Uselul  Information  for  Employers  of  Labor. 
Foremen  and  Working  Boiler-Makers.  Iroa,  Copper,  and  Tinsmiths 


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Draughtsmen,  Engineers,  the  General  Steam-using  Public,  and  for  thd 
Use  of  Science  Schools  and  Classes.  By  Samuel  NlCHOLLS.  Illus- 
trated by  sixteen  plaies,  121110.  .....  #2.50 

NICHOLSON. — A  Manual  of  the  Art  of  Bookbinding : 

Containing  full  instructions  in  the  different  Branches  of  Forwarding, 
Gilding,  and  Finishing.  Also,  the  Art  of  Marbling  Book-edges  and 
Paper.    By  James  B.  Nicholson.    Illustrated.  i2mo.,  cloth  #2.25 

NICOLLS.— The  Railway  Builder: 

A  Hand-Book  for  Estimating  the  Probable  Cost  of  American  Rail* 
way  Construction  and  Equipment.  By  William  J.  Nicolls,  Civil 
Engineer.   Illustrated,  full  bound,  pocket-book  form 

NORMANDY. — The  Commercial  Handbook  of  Chemical  An- 
alysis : 

Or  Practical  Instructions  for  the  Determination  of  the  Intrinsic  01 
Commercial  Value  of  Substances  used  in  Manufactures,  in  Trades, 
and  in  the  Arts.  By  A.  Normandy.  New  Edition,  Enlarged,  and 
to  a  great  extent  rewritten.    By  Henry  M.  Noad,  Ph.D.,  F.R.S., 

thick  i2mo  $$.oc 

NORRIS. — A  Handbook  for  Locomotive  Engineers  and  Ma- 
chinists : 

Comprising  the  Proportions  and  Calculations  for  Constructing  Loco, 
motives;  Manner  of  Setting  Valves;  Tables  cf  Squares,  Cubes,  Areas, 
etc.,  etc.  By  Septimus  Norris,  M.  E.  New  edition.  Illustrated, 
I2mo  $1.50 

NVSTROM. — A  New  Treatise  on  Elements  of  Mechanics  : 
Establishing  Strict  Precision  in  the  Meaning  of  Dynamical  Terms: 
accompanied  with  an  Appendix  on  Duodenal  Arithmetic  and  Me 
trology.    By  John  W.  Nystrom,  C.  E.    Illustrated.    8vo.       #3. 00 

NYSTROMl— On  Technological  Education  and  the  Construc- 
tion of  Ships  and  Screw  Propellers: 
For  Naval  and  Marine  Engineers.    By  John  W.  Nystrom,  lata 
Acting  Chief  Engineer,  U.  S.  N.    Second  edition,  revised,  with  addi- 
tional matter.    Illustrated  by  seven  engravings.     l2tno.    .  $1-25 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing: 

Containing  a  brief  account  of  all  the  Substances  and  Piocesses  in 
use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics  ;  with  Practical 
Receipts  and  Scientific  Information.  By  Charles  O'Neill,  Analy- 
tical Chemist.  To  which  is  added  an  Essay  on  Coal  Tar  Colors  and 
their  application  to  Dyeing  and  Calico  Printing.  By  A.  A.  Fesquet, 
Chemist  and  Engineer.  With  an  appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867-  8vo., 
49 1  pages         .        .   $3-00 

ORTON. — Underground  Treasures-. 

Hew  and  Where  to  Find  Them.  A  Key  for  the  Ready  Determination 
t>f  ail  the  Useful  Minerals  within  the  United  States.  By  James 
OrToN,  A.M.,  Late  Professor  of  Natural  History  in  Vassar  College, 
N.  Y.;  Cor.  Mem.  of  the  Academy  of  Natural  Sciences,  Philadelphia, 
and  of  the  Lyceum  of  Natural  History,  New  York  ;  author  of  the 
'Andes  and  the  Amazon,"  etc.  A  New  Edition,  with  Additions. 
'Uustratsd   $1.50 


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OSBORN  —  The  Prospector's  Field  Book  and  Guide. 

In  the  Search  For  and  the  Easy  Determination  of  Ores  and  Other 
Useful  Minerals.  By  Prof  H.  S.  Osborn,  LL.  D.  Illustrated  by  58 
Engravings.  i2mo.  Fourth  Edition.  Revised  and  Enlarged 
(1899)  $1.50 

OSBORN— A  Practical  Manual  of  Minerals,  Mines  and  Min- 
ing: 

Comprising  the  Physical  Properties,  Geologic  Positions,  Local  Occur- 
rence and  Associations  of  the  Useful  Minerals;  their  Methods  of 
Chemical  Analysis  and  Assay  ;  together  with  Various  Systems  of  Ex- 
cavating and  Timbering,  Brick  and  Masonry  Work,  during  Driving, 
Lining,  Bracing  and  other  Operations,  etc.    By  Prof.  H.  S.  Osborn, 
LL.  D.,  Author  of  "The  Prospector's  Field-Book  and  Guide."  171 
engravings.    Second  Edition,  revised.    8vo.     .       .       .  #4.50 
OVERMAN. — Th«  Manufacture  of  Steel : 
Containing  the  Practice  and  Principles  of  Working  and  Making  Steel. 
A  Handbook  for  Blacksmiths  and  Workers  in  Steel  and  Iron,  Wagon 
Makers,  Die  Sinkers,  Cutlers,  and  Manufacturers  of  Files  and  Hani- 
ware,  of  Sb'el  and   iron,  and  for  Men  of  Science  and  Art.  By 
FREDERICK  OVERMAN,  Mining  Engineer,  Author  of  the  "  Manu- 
facture of  Lon,"  etc.    A  new,  enlarged,  and  revised  Edition.  By 
A.  A.  FESQUET,  Chemist  and  Engineer.    l2mo.       .       .  $1.50 
OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide  : 
A  Treatise  or.  Moulding  and  Founding  in  Green-sand,  Dry  sand,  Loam, 
and  Cement;  the  Moulding  of  Machine  Frames,  Mill-gear,  Hollow- 
ware,  Ornamer's,  Trinkets,  Bells,  and  Statues;  Description  of  Moulds 
for  Iron,  Bronze,  Brass,  and  other  Metals;  Plaster  of  Paris,  Sulphur, 
Wax,  etc. ;  the  Construction  of  Melting  Furnaces,  the  Melting  and 
Founding  of  Metals  ;  the  Composition  of  Alloys  and  their  Nature, 
etc.,  etc.    By  FREDERICK  Overman,  M.  E.    A  new  Edition,  to 
which  is  added  a  Supplement  on  Statuary  and  Ornamental  Moulding, 
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ist and  Engineer.    Illustrated  by  44  engravings.    I2mo.  .  $2.00 
PAINTER,  GILDER.  AND  VARNISHER'S  COMPANION. 
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ing, Graining,  Marbling,  Staining,  Sign  writing,  Varnishing,  Glass- 
staining,  and  Gilding  on  Glass;  together  with  Coach  Panning  and 
Varnishing,  and  the  Principles  of  the  Harmony  and  Contrast  of 
Colors.    Twenty-seventh  Edition.     Revised,  Enlarged,  and  in  great 
part  Rewritten.    By  William  T.  Brannt.  Editor  of  "Varnishes. 
Lacquers,  Printing  Inks  and  Sealing  Waxes."     Illustrated.    395  pp. 

I2mo.  ,   $1  50 

PALLETT  —  The  Miller's,  Millwright's, and  Engineer's  Guide 
By  Henry  Pallett.    Illustrated.    i2mo.      .  $2.00 


22        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


PERCY.— The  Manufacture  of  Russian  Shset-Iron. 

Bv  John  Percy,  M.  D.,  F.  R.  S.  Paper.  ...  25  cts. 
PERKINS. — Gas  and  Ventilation: 

Practical  Treatise  on  Gas  and  Ventilation.  Illustrated.  l2mo.  $1.25 
PERKINS  AND  STOWE.-A  New  Guide  to  the  Sheet-iron 
and  Boiler  Plate  Roller  : 
Containing  a  Series  of  Tables  showing  the  Weight  of  Slabs  and  Piles 
to  Produce  Boiler  Plates,  and  of  the  Weight  of  Piles  and  the  Sizes  of 
Bars  to  produce  Sheet-iron ;  the  Thickness  of  the  Bar  Gaug« 
in  decimals;  the  Weight  per  foot,  and  the  Thickness  on  the  Bar  or 
Wire  Gauge  of  the  fractional  parts  of  an  inch;  the  Weight  per 
sheet,  and  the  Thickness  on  the  Wire  Gauge  of  Sheet-iron  of  various 
dimensions  to  weigh  112  lbs.  per  bundle;  and  the  conversion  of 
Short  Weight  into  Long  Weight,  and  Long  Weight  into  Short. 

$1.50 

POSSELT.— Recent  Improvements  in  Textile  Machinery  Re- 
lating to  Weaving : 

Giving  the  Most  Modern  Points  on  the  Construction  of  all  Kinds 
of  Looms,  Warpers,  Beamers,  Slashers,  Winders,  Spoolers,  Reeds, 
Temples,  Shuttles,  Bobbins,  Heddles,  Heddle  Frames,  Pickers, 
Jacquards,  Card  Stampers,  etc.,  etc.  600  illus.  .  .  S3  00 
POSSELT. — Technology  of  Textile  Design: 

The  Most  Complete  Treatise  on  the  Construction  and  Application 
of  Weaves  for  all  Textile  Fabrics  and  the  Analysis  of  Cloth.    By  E. 

A.  Posseit.     1,500  illustrations.    4to  $5-00 

POSSELT. — Textile  Calculations: 

A  Guide  to  Calculations  Relating  to  the  Manufacture  of  all  Kinds 
of  Yarns  and  Fabrics,  the  Analysis  of  Cloth,  Speed,  Power  and  Belt 
Calculations.    By  E.  A.  Posselt.    Illustrated.    4to.       .  $2.00 
REGNAULT.— Elements  of  Chemistry: 

By  M.  V.  Regnault.  Translated  from  the  French  by  T.  Forrest 
Betton,  M.  D.,  and  edited,  with  Notes,  by  James  C.  Booth,  Melter 
and  Refiner  U.  S.  Mint,  and  William  L.  Faber,  Metallurgist  and 
Mining  Engineer.  Illustrated  by  nearly  700  wood-engravings.  Com- 
prising nearly  1,500  pages.  In  two  volumes,  8vo.,  cloth  .  $6.00 
RICHARDS. — Aluminium  : 

Its  History,  Occurrence,  Properties,  Metallurgy  and  Applications, 
including  its  Alloys.  By  Joseph  W.  Richards,  A.  C,  Chemist  and 
Practical  Metallurgist,  Member  of  the  Deutsche  Chemische  Gesell- 
schaft.  Illust.  Third  edition,  enlarged  and  revised  (1895)  .  #6.00 
RIFFAULT,  VERGNAUD,  and  TOUSSAIMT. — A  Practical 
Treatise  on  the  Manufacture  of  Colors  for  Painting: 
Comprising  the  Origin,  Definition,  and  Classification  of  Colors;  the 
Treatment  of  the  Raw  Materials;  the  best  Formulae  and  the  Newest 
Processes  for  the  Preparation  of  every  description  of  Pigment,  and 
the  Necessary  Apparatus  and  Directions  for  its  Use;  Divers;  ih» 
Vesting.  Application,  and  Qualities  of  Paints,  etc.,  etc.  By  MM. 
RlFFAULT,  Vekgnaud,  and  Toussaiwt.    Revised  and  Edited  by  M. 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  23 

F.  Malepeyre.  Translated  from  the  French,  by  A.  A.  Fesqit«1> 
Chemist  and  Engineer.  Illustrated  by  Eighty  engravings.  In  one 
vol..  8vo.,  659  pages  $5.00 

ROPER.— A  Catechism  of  High-Pressure,  or  Non-Condensing 
Steam-Engines  : 
Including  the  Modelling,  Constructing,  and  Management  of  Steam- 
Engines  and  Steam  Boilers.  With  valuable  illustrations.  By  STE- 
PHEN Roper.  Engineer.  Sixteenth  edition,  revised  and  enlarged. 
[8mo.,  tucks,  gilt  edge  $2.00 

f-  OPER.— Engineer's  Handy-Book : 
Containing  a  full  Explanation  of  the  Steam-Engine  Indicator,  and  its 
Use  and  Advantages  to  Engineers  and  Steam  Users  With  Formula 
for  Estimating  the  Power  of  all  Classes  of  Steam-Engines;  also. 
Facts,  Figures,  Questions,  and  Tables  for  Engineers  who  wish  to 
qualify  themselves  lor  the  United  States  Navy,  ihe  Revenue  Service, 
the  Mercantile  Marine,  or  to  take  charge  of  the  Better  Class  of  Sta- 
tionary Steam-Engines.  Tenth  edition.  l6rao..  690  pages,  tucks, 
gilt  edge  £3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines  : 
Including  ih-  Modelling,  Construction,  Running,  and  Management 
of  Lain'  and  Marine  Engines  anrl  Boilers.    With  illustrations,  riy 
Stephen  Roper,  Engineer.   Sixth  edition.    121110., ti  cks,  gilt  edge. 

#3-50 

ROPER.  — Hand-Book  of  the  Locomotive: 

Including  the  Construction  of  Engines  and  Boilers,  and  the  Construc- 
tion, Management,  and   Running  of  Locomotives.    By  Stephen 
Roper.    Eleventh  edition.    l8mo.,  tucks,  gilt  edge         .  $2.50 
ROPER.— Hand-Book  of  Modern  Steam  Fi'e-Engines. 

With  illustrations.     By  STEPHEN  Roper,  Engineer.     Fourth  edition, 
1 2mo.,  tucks,  gilt  edge      .......  $3-S° 

ROPER. — Questions  and  Answers  for  Engineers. 

This  little  book  contains  all  the  Questions  that  Engineers  will  be 
asked  when  undergoing  an  Examination  for  the  purpose  of  procuring 
Licenses,  and  they  are  so  plain  that  any  Engineer  or  Fireman  of  or 
dinary  intelligence  may  commit  them  to  memory  in  a  short  time.  By 
Stephen  Roper,  Engineer.    Third  edition  .       .  $2.00 

ROPER.— Use  and  Abuse  of  the  Steam  Boiler. 

By  Stephen  Roper,  Engineer.    Eighth  edition,  with  illustrations. 

l8mo.,  tucks,  gilt  eilge  #2.00 

ROSE. — The  Complete  Practical  Machinist : 

Embracing  Lathe  Work,  Vise  Work,  Drills  and  Drilling,  Taps  and 
Dies,  Hardening  and  Tempering,  the  Making  and  Use  of  Tools. 
Tool  Grinding,  Marking  out  Work,  Machine  Tools,  etc.  By  Joshua 
Rose.  39;  Engravings.  Nineteenth  Edition,  greatly  Enlarged  with 
New  and  Valuable  Matter.  I2mo.,  504  pages.  .  .  $2.50 
ROSE —Mechanical  Drawing  Self-Taught: 

Comprising  Instructions  in  the  Selection  and  Preparation  of  Drawing 
Instruments.  Elementary  Instruction  in  Practical  Mechanical  Draw- 


24       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


ing,  together  with  Examples  in  Simple  Geometry  and  Elementary 
Mechanism,  including  Screw  Threads,  Gear  Wheels,  Mechanical 
Motions,  Engines  and  Boilers.  By  Joshua  Rose,  M.  E.  Illustrated 
by  330  engravings.    8vo  ,  313  pages        ....  $400 

ROSE. — The  Slide- Valve  Practically  Explained: 

Embracing  simple  and  complete  Practical  Demonstrations  of  th 
operation  of  each  element  in  a  Slide-valve  Movement,  and  illustrat- 
ing the  effects  of  Variations  in  their  Proportions  by  examples  care- 
fully selected  from  the  most  recent  and  successful  practice.  By 
Joshua  Rose,  M.  E.    Illustrated  by  35  engravings         .  $1.00 

ROSS. — The  Blowpipe  in  Chemistry,  Mineralogy  and  Geology: 
Containing  all  Known  Methods  of  Anhydrous  Analysis,  many  Work- 
ing Examples,  and  Instructions  for  Making  Apparatus.  By  LlEUT.- 
Colonel  W.  A.  Ross,  R.  A.,  F.  G.  S.  With  120  Illustrations. 
121110.      ..........  #2.00 

SHAW.— Civil  Architecture : 

Being  a  Complete  Theoretical  and  Practical  System  of  Building,  con- 
taining  the  Fundamental  Principles  of  the  Art.  By  Edward  Shaw, 
Architect.  To  which  is  added  a  Treatise  on  Gothic  Architecture,  etc. 
By  Thomas  W.  Sili.oway  and  George  M.  Harding,  Architects. 
The  whole  illustrated  by  102  quarto  plates  finely  engraved  on  copper. 
Eleventh  edition.    4to.    .......  $6.00 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and  Loca- 
tion, for  Young  Engineers. 

By  W.  F.  Shunk,  C.  E.    121110.    Full  bound  pocket-book  form  $2. 00 

SLATER.— The  Manual  of  Colors  and  Dye  Wares. 

By  J.  W.  Slater.    i2mo  #3.00 

SLOAN. — American  Houses: 

A  variety  of  Original  Designs  for  Rural  Buildings.    Illustrated  by 
26  colored  engravings,  with  descriptive  references.     By  Samuel 
Sloan,  Architect.    8vo.         ......  .75 

SLOAN. — Homestead  Architecture: 

Cjntaini.:^  Forty  Designs  for  Villas,  Cottages,  and  Farm-houses,  witb 
EiSiys  on  Styiv.,  Construction,  Landscape  Gardening,  Furniture,  etc., 
etc.  7 'lustrated  by  upwards  of  200  engravings.  By  Samuel  Sloan, 
Architect.    8vo.      ...       .....  $2.50 

SLOANE.  — Ho.re  Experiments  in  Science. 

By  T.  O'Conor  Slcne,  E.  M.,  A.M.,  Ph.D.  Illustrated  by  91 
engravings.    i2mo.         .......  $1.00 

SMEATON.— Builder's  Pockti -Companion  : 

•    Containing  the  Elements  of  Building,  Surveying,  and  Architecture ; 

with  Practical  Rules  and  Instructions  corrected  with  the  subject. 

By  A.  C.  Smeaton,  Civil  Engineer,  etc.  i2mo.  .  .  75  cts. 
SMITH. — A  Manual  of  Political  Economy. 

By  E.  Peshine  Smith.    A  New  Edition,  to  which  is  added  a  full 

Index.    l2mo.        ........       *i  ^5 


HENRY  CAREY  LaIRD  6l  CO.'S  CATALOGUE.  25 


SMITH  —Parks  and  Pleasure-Grounds : 

Or  Practical  Notes  on  Country  Residences,  Villas,  Public  Parks,  and 
Gardens.  By  Charles  H.  J.  Smith,  Landscape  Gardener  and 
Garden  Architect,  etc.,  etc.    121110.  ....  $2.00. 

SMITH.— The  Dyer's  Instructor: 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk,  Cotton, 
Wool,  and  Worsted,  and  Woolen  Goods ;  containing  nearly  Hoc 
Receipts.  To  which  is  added  a  Treatise  on  the  Art  of  Padding;  ancj 
the  Printing  of  Silk  Warps,  Skeins,  and  Handkerchiefs,  and  the) 
various  Mordants  and  Colors  for  the  different  styles  of  such  work.' 
By  David  Smith,  Pattern  Dyer.    i2mo.         .       .       .      $1. 50 

SMYTH.— A  Rudimentary  Treatise  on  Coal  and  Coal-Mining. 
By  Warrington  W.  Smyth,  M.  A.,  F.  R  G.,  President  R.  G.  S. 
of  Cornwall.  Fifth  edition,  revised  and  corrected.  With  f.umer- 
ous  illustrations.    l2mo.  ......       ^ 1 .75 

SNIVELY. — Tables  for  Systematic  Qualitative  Chemical  AnaK 
ysis. 

Hy  John  H.  Snively,  Phr.  D.    8vo  $1.00 

SNIVELY. — The  Elements  of  Systematic  Qualitative  vhemical 
Analysis  : 

A  Hand-book  for  Beginners.   By  John  H.  SNIVELY,  Phr.  D.  l6mo. 

$2.00 

STOKES. — The  Cabinet  Maker  and  Upholsterer's  Companion; 

Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet  Work; 
Veneering,  Inlaying,  and  Buhl- Work;  the  Art  of  Dyeing  and  Stain 
ing  Wood,  Ivory,  Bone,  Tortoise-Shell,  etc.  Directions  for  Lacker- 
ing, Japanning,  and  Varnishing;  to  make  French  Polish,  Glues. 
Cements,  and  Compos'.:' ns;  with  numerous  Receipts,  useful  to  work 
men  generally.  Bv  STOKES.  Illustrated.  A  New  Edition,  with 
an  Appendix  upor    .ench  Polishing,  Staining,  Imitating,  Varnishing, 

etc.,  etc.   i2mo  $1.25 

STRENGTH  AND  OTHER  PROPERTIES  OF  METALS; 
Reports  of  Experiments  on  the  Strength  and  other  Properties  of 
Metals  for  Cannon.  With  a  Descri|itiuii  of  the  Machines  for  Testing 
Metals,  and  of  the  Classification  of  Cannon  in  service.    By  Officers 


of  the  Ordnance  Department,  U.  S.  Army.     By  authority  of  the  Secre- 
tary of  War.     Illustrated  by  25  large  steel  plates.   Quarto  #5.00 
SULLIVAN. — Protection  to  Native  Industry. 
By  Sir  Edward  Sullivan,  Baronet,  author  of  "Ten  Chapters  on 

Social  Reforms."    8vo  $100 

SH  ERR  ATT. — The  Elements  of  Hand-Railing: 


Simplified  and  Explained  in  Concise  Problems  that  are  Easily  Under- 
stood. The  whole  illustrated  with  Thirty-eight  Accurate  and  Origi- 
nal Plates,  Founded  on  Geometrical  Principles,  and  Showing  how  to 
Make  Rail  Without  Centre  Joints,  Making  Better  Rail  of  the  Same 
Material,  with  Half  the  Labor,  and  Showing  How  to  Lay  Out  Stairs 
ol  all  Kinds.     By  R.  J.  Shkrratt.    Folio.     .       .       .  $2.50 


o«       HENRY  CAREY  BAIRt»  &  CO.'S  CATALOGUE. 


SYME. — Outlines  of  an  Industrial  Science. 
By  David  Syme.    121110.        .       .  ...  $2.00 

TABLES    SHOWING    THE    WEIGHT    OF  ROUND, 
SQUARE,  AND  FLAT  BAR  IRON,  STEEL,  ETC., 

By  Measurement.    Cloth  ......  63 

TAYLOR.— Statistics  of  Coal : 

Including  Mineral  Bituminous  Substances  employed  in  Arts  and 
Manulactures ;  with  their  Geographical,  Geological,  and  Commercial 
Distribution  and  Amount  of  Production  and  Consumption  on  the 
American  Continent.  With  Incidental  Statistics  of  the  Iron  Manu- 
facture. By  R.  C.  Taylor.  Second  edition,  revised  by  S.  S.  Halde* 
MAN.    Illustrated  by  five  Maps  and  many  wood  engravings.  8vo.r 

cloth  $6.00 

TEMPLETON  —  The  Practical  Examinator  on  Steam  and  the 
Steam -Engine: 
With  Instructive  References  relative  thereto,  arranged  for  the  Use  of 
Engineers,  Students,  and  others.    By  William  Templeton,  En- 
gineer.    I2mo.         ........  $1.00 

THAUSING. — The  Theory  and  Practice  of  the  Preparation  of 
Malt  and  the  Fabrication  of  Beer: 
With  especial  reference  to  the  Vienna  Process  of  Brewing.  Elab- 
orated from  personal  experience  by  Julius  E.  Thausing,  Professor 
at  the  School  for  Brewers,  and  at  the  Agricultural  Institute,  Modling, 
near  Vienna.  Translated  from  the  German  by  William  T.  Brannt, 
Thoroughly  and  elaborately  edited,  with  much  American  matter,  and 
according  to  the  latest  and  most  Scientific  Practice,  by  A.  Schwarz 
and  Dr.  A.  U.  BAUER.     Illustrated  by  140  Engravings.    8vo.,  8 1 5 

pages  $10.00 

THOMAS.— The  Modern  Practice  of  Photography: 

By  R.  W.  Thomas,  F.  C.*S.    8vo.  ....  25 

THOMPSON.— Political  Economy.    With  Especial  Reference 
to  the  Industrial  History  of  Nations  : 
By  Roisert  E.  Thompson,  M.  A.,  Professor  of  Social  Science  in  the 
University  of  Pennsylvania.    l2mo.         ....  $1.50 
THOMSON.— Freight  Charges  Calculator: 

By  Andrew  Thomson,  Freight  Agent.  241110.  .  .  $1.25 
TURNER'S  (THE)  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric  Turn, 
irig;  also  various  Plates  of  Chucks,  Tools,  and  Instruments;  and 
Directions  for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and 
Circular  Rest;  with  Patterns  and  Instructions  for  working  them. 

1 21110  $1.00 

TURNING:  Specimens  of  Fancy  Turning  Executed  on  the 
Hand  or  Foot-Lathe : 
With  Geometric,  Oval,  and  Eccentric  Chucks,  and  Elliptical  Cutting 
Frame.    By  an  Amateur.    Illustrated  by  30  exquisite  Photographs. 
4to.  .   $2.50 


HEN R V  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


VAILE.— Galvanized-Iron  Cornice- Worker's  Manual: 

Containing  Instructions  in  Laying  out  the  Different  Mitres,  and 
Making  Patterns  for  all  kinds  of  Plain  and  Circular  Work.  Also, 
Tables  of  Weights,  Areas  and  Circumferences  of  Circles,  and  other 
Matter  calculated  to  Benefit  the  Trade.  By  Charles  A.  Vaile. 
Illustrated  by  twenty-one  plates.    4to.        ....  $5.00 

VILLE. — On  Artificial  Manures  : 
Their  Chemical  Selection  and  Scientific  Application  to  Agriculture. 
A  series  of  Lectures  given  at  the  Experimental  Farm  at  Vincennes, 
during  1867  and  1S74-75.  By  M.  Georges  Ville.  Translated  and 
Edited  by  William  Crookes,  F.  R.  S.  Illustrated  by  thirty-one 
engravings.   8vo.,  450  pages     ......  56.00 

VILLE.— The  School  of  Chemical  Manures  : 
Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents.  From 
the  French  of  M.  Geo.  Ville,  by  A.  A.  Fesquet,  Chemist  and  En- 
gineer.   With  Illustrations.    l2mo.         ....  $1.25 

VOGDES. — The  Architect's  and  Builder's  Pocket-Companion 
and  Price-Book  : 
Consisting  of  a  Shoit  but  Comprehensive  Epitome  of  Decimals,  Duo- 
decimals, Geometry  and  Mensuration  ;  with  Tables  of  United  States 
Measures,  Sizes,  Weights,  Strengths,  etc.,  of  Iron,  Wood,  Stone, 
3rick,  Cement  and  Concretes,  Quantities  of  Materials  in  given  Sizes 
and  Dimensions  of  Wood,  Brick  and  Stone;  and  full  and  complete 
Bilis  of  Prices  for  Carpenter's  Work  and  Painting ;  also,  Rules  for 
Computing  and  Valuing  Brick  and  Brick  Work,  Stone  Work,  Paint- 
ing, Plastering,  with  a  Vocabulary  of  Technical  Terms,  etc.  By 
Frank  VV.  Vogdes,  Architect,  Indianapolis,  Ind.  Enlarged,  revised, 
and  corrected.    In  one  volume,  368  pages,  full-bound,  pocket-book 

form,  gilt  edges  $2.00 

Cloth       .       .   I.50 

VAN  CLEVE. — The  English  and  American  Mechanic: 

Comprising  a  Collection  of  Over  Three  Thousand  Receipts,  Rules, 
and  Tables,  designed  for  the  Use  of  every  Mechanic  and  Manufac- 
turer. By  B.  Frank  Van  Cleve.  Illustrated.  500  pp.  i2mo.  $2.00 

WAHNSCHAFFE. — A  Guide  to  the  Scientific  Examination 
of  Soils: 

Comprising  Select  Methods  of  Mechanical  and  Chemical  Analysis 
and  Physical  Investigation.  Translated  from  the  German  of  Dr.  F. 
WAHNSCHAFFE.  With  additions  by  WILLIAM  T.  Brannt.  Illus- 
trated by  25  engravings.    121110.    177  pages    .       .       .  $1.50 

WALL. — Practical  Graining: 

With  Descriptions  of  Colors  Employed  and  Tools  Used.  Illustrated 
by  47  Colored  Plates,  Representing  the  Various  Woods  Used  X 
Interior  Finishing.    By  William  E.  Wall.    8vo.       .  #2.50 

WALTON. — Coal-Mining  Described  and  Illustrated: 

By  Thomas  H.  Walton,  Mining  Engineer.  Illustrated  by  24  Jarge 
and  elaborate  Plates,  after  Actual  Workings  and  Apparatus.  P5.0C 


2S        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


IVARE. — The  Sugar  Beet. 

Including  a  History  of  the  Beet  Sugar  Industry  in  Europe,  Varietie 
ol  the  Sugar  Beet,  Examination,  Soils,  Tillage,  Seeds  and  Sowing 
Yield  and  Cost  of  Cultivation,  Harvesting,  Transportation,  Conserva 
Hon,  Feeding  Qualities  of  the  Beet  and  of  the  Pulp,  etc.  By  Lewis 
S.  Ware,  C.  E.,  M.  E.    Illustrated  by  ninety  engravings.  8vo. 

WARN. — The  Sheet-Metal  Worker's  Instructor: 

For  Zinc,  Sheet- Iron,  Copper,  and  Tin- Plate  Workers,  etc.  Contain- 
ing a  selection  of  Geometrical  Problems;  also,  Practical  and.  Simple 
Rules  for  Describing  the  various  Patterns  required  in  the  different 
branches  of  the  above  Trades.  By  Reuben  H.  Warn,  Practical 
Tin- Plate  Worker.  To  which  is  added  an  Appendix,  containing 
Instructions  lor  Boiler-Making,  Mensuration  of  Surfaces  and  Solids, 
Rules  for  Calculating  the  Weights  of  different  Figures  of  Iron  and 
Steel,  Tables  of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty 
two  Plates  and  thirty-seven  Wood  Engravings.    8vo.        .  #3.00 

WARNER. — New  Theorems,  Tables,  and  Diagrams,  for  the 
Computation  of  Earth-work  : 

Designed  for  the  use  of  Engineers  in  Preliminary  and  Final  Estimates 
of  Students  in  Engineering,  and  of  Contractors  and  other  non-profes- 
sional Computers.  In  two  parts,  with  an  Appendix.  Part  I.  A  Prac- 
tical Treatise;  Part  II.  A  Theoretical  Treatise,  and  the  Appendix. 
Containing  Notes  to  the  Rules  and  Examples  of  Part  I.;  Explana- 
tions of  the  Construction  of  Scales,  Tables,  and  Diagrams,  and  a 
Treatise  upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
By  John  Warner,  A.  M.,  Mining  and  Mechanical  Engineer.  Illus- 
trated by  14  Plates.    8vo.  $4.00 

WILSON. — Carpentry  and  Joinery  -. 

By  John  Wilson,  Lecturer  on  Building  Construction,  Carpentry  and 
Joineiy,  etc.,  in  the  Manchester  Technical  School.  Third  Edition, 
with  65  full  page  plates,  in  flexible  cover,  oblong      .       .  .80 

WATSON. — A  Manual  of  the  Hand-Lathe  : 

Comprising  Concise  Directions  for  Working  Metals  of  all  kinds, 
Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring,  and  French 
Polishing;  Inlaying  by  Veneers,  and  various  methods  practised  to 
produce  Elaborate  work  with  Dispatch,  and  at  Small  Expense.  By 
Egbert  P.  Watson,  Author  of  "  The  Modern  Practice  of  American 
Machinists  and  Engineers."    Illustrated  by  78  engravings.        $t. 50 

WATSON. — The  Modern  Practice  of  American  Machinists  and 
Engineers 

Including  the  Construction,  Application,  and  Use  of  Drills,  Lattie 
Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work  generally ,  with 
the  most  Economical  Speed  for  the  same  ;  the  Results  verified  by 
Actual  Practice  at  the  Lathe,  the  Vise,  and  on  the  Floor.  Togetha 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  29 


with  Workshop  Management,  Economy  of  Manufacture,  the  Steam 
Engine,  Boilers,  Gears,  Belling,  etc.,  etc.  By  Egbert  P.  Watson. 
Illustrated  by  eighty-six  engravings.     l2mo.      .        .        .  $2.50 

WATT.— The  Art  of  Soap  Making  : 

A  Practical  Iland-Book  of  the  Manufacture  of  Hard  and  Soft  Soaps, 
Toilet  Soaps,  etc.  Fifth  Edition,  Revised,  to  which  is  added  an 
Appendix  on  Modern  Candle  Making.  By  Alexander  Watt. 
111.    121110.  $3.00 

WEATHERLY  —  Treatise  on  the  Art  of  Boiling  Sugar,  Crys- 
tallizing, Lozenge-making,  Comfits,  Gum  Goods, 
And  other  processes  for  Confectionery,  etc.,  in  which  aie  explained, 
in  an  easy  and  familiar  manner,  the  various  Methods  of  Manufactur- 
ing every  Description  of  Raw  and  Refined  Sugar  Goods,  as  sold  by 
Confectioners  and  others.    l2mo.     .....       $1 .50 

WILL.— Tables  of  Qualitative  Chemical  Analysis  : 

With  an  Introductory  Chapter  on  the  Course  of  Analysis.  By  Pro- 
fessor HEINRICH  Will,  of  Giessen,  Germany.  Third  American, 
from  the  eleventh  German  edition.  Edited  by  Charles  F.  Himes, 
Ph.  D.,  Professor  of  Natural  Science,  Dickinson  College,  Carlisle, 
Pa.    8vo  $1.50 

WILLIAMS. — On  Heat  and  Steam  : 

Embracing  New  Views  of  Vaporization,  Condensation  and  Explo- 
sion.   By  Charles  Wye  Williams,  A.  I.  C.  E.   Illustrated.  8vo. 

£2.50 

WILSON. — First  Principles  of  Political  Economy: 

With  Reference  to  Statesmanship  and  the  Progress  of  Civilization. 
By  Professor  W.  D.  Wilson,  of  the  Cornell  University.  A  new  and 
revised  edition.    l2mo.    .......  $l-S° 

WILSON.— The  Practical  Tool-Maker  and  Designer: 

A  Treatise  upon  the  Designing  of  Tools  and  Fixtures  for  Machine 
Tools  and  Melal  Working  Machinery,  Comprising  Modern  Examples 
of  Machines  with  Fundamental  Designs  for  Tools  for  the  Actual  Pro- 
duciion  of  the  work;  Together  with  Special  Reference  to  a  Set  of 
Tools  for  Machining  the  Various  Parts  of  a  Bicycle.  Illustrated  by 
189  engravings.    1898  $2.50 

CONTENTS:  Introductory.  Chapter  I.  Modern  Tool  Room  and  Equipment. 
II.  Files,  Their  Use  and  Abuse.  III.  Steel  and  Tempering.  IV.  Making  Jigs. 
V.  Milling  Machine  H ixtures.  VI  'fools  and  Fixtures  for  Screw  Machines  VII. 
Broaching,  VIII.  Punches  and  Dies  for  Cutting  and  Drop  Pi  ess.  IX.  Tools  for 
Hollow-Ware.  X  Embossing:  Metal,  Com,  and  Siamped  Sheet-Metal  Orna- 
ments. XI.  Drop  Forging  XII.  Solid  Drawn  Shells  or  Ferrules;  Cupping  or 
Cutting,  and  Drawing:  Breaking  Down  Shells  XIII.  Annealing,  Picking  and 
Cleaning.  XIV.  Tools  for  Draw  Bench.  XV.  Cutting  and  Assembling  Pieces 
by  Means  of  Ratchet  Dial  Plates  at  One  Operation.  XVI.  The  Header.  XVII. 
Tools  for  Fox  Lathe.  XVIII  Suggestions  lor  a  Set  of  Tools  for  Machining  the 
Various  Parts  of  a  Bicycle.  XIX  The  Plater's  Dynamo.  XX.  Conclusion— 
With  a  Few  Random  Ideas  Appendix.  Index. 
WOODS. — Compound  Locomotives: 

By  ARTHUR  Tannatt  Woods.  Second  edition,  revised  and  enlarged 
by  David  Leonard  Barnes,  A  M.,  C.  E.    8vo.    330  pp.      $3  00 


3P       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


WOHLER. — A  Hand-Bookof  Mineral  Analysis: 

By  F.  WoHLER,  Professor  of  Chemistry  in  the  University  of  Gottin- 
gen.  Edited  by  Henry  B.  Nason,  Professor  of  Chemistry  in  the 
Renssalaer  Polytechnic  Institute,  Troy,  New  York.  Illustrated. 
I2mo   $2.50 

WORSSAM.— On  Mechanical  Saws: 

From  the  Transactions  of  the  Society  of  Engineers.  1 869.  By  S.  W. 
Worssam,  Jr.    Illustrated  by  eighteen  large  plates.   8vo.  $1.50 


RECENT  ADDITIONS. 

BRANNT. — Varnishes,  Lacquers,  Printing  Inks  and  Sealing - 

Waxes  : 

Their  Raw  Materials  and  their  Manufacture,  to  which  is  added  the 
Art  of  Varnishing  and  Lacquering,  including  the  Preparation  of  Put- 
ties and  of  Stains  for  Wood,  Ivory,  Bone,  Horn,  and  Leather.  By 
William  T.  Brannt.    Illustrated  by  39  Engravings,  338  pages. 

i2mo   .  #3.°o 

BRANNT — The  Practical  Scourer  and  Garment  Dyer: 

Comprising  Dry  or  Chemical  Cleaning;  the  Art  of  Removing  Stains, 
Fine  Washing;  Bleaching  an»l  Dyeing  of  Straw  Hats,  Gloves,  and 
Feathers  of  all  kinds;  Dyeing  of  Worn  Clothes  of  all  fabrics,  in- 
cluding Mixed  Goods,  by  One  Dip;  and  the  Manufacture  of  Soaps 
and  Fluids  for  Cleansing  Purposes.  Edited  by  Willi  AM  T.  BRANNT, 
Editor  of  "The  Techno-Chemical  Receipt  Book."  Illustrated. 
203  pages.    i2mo.       ....       .       .       .       .       .  $2.00 

BRANNT. — Petroleum . 

its  History,  Origin,  Occurrence,  Production,  Physical  and  Chemical 
Constitution,  Technology,  Examination  and  Uses;  Together  with 
the  Occurrence  and  U>es  of  Natural  Gas.  Edited  chiefly  from  the 
German  of  Prof.  Hans  Hoefer  and  Dr.  Alexander  Veith,  by  Wm. 
T.  Brannt.  Illustrated  by  3  Plates  and  284  Engravings.  743  pp. 
8vo.  #7.50 
BRANNT. — A  Practical  Treatise  on  the  Manufacture  of  Vine- 
gar and  Acetates,  Cider,  and  Fruit-Wines: 
Preservation  of  Fruits  and  Vegetables  by  Canning  and  Evaporation; 
Preparation  of  Fruit-Butters,  Jellies,  Marmalades,  Catchups,  Pickles, 
Mustards,  etc.  Edited  from  various  sources.  By  William  T. 
Brannt.    Illustrated  by  79  Engravings.    479  pp.    8vo.  $0.00 

BRANNT.— The  Metal  Worker's  Handy-Book  of  Receipts 
and  Processes : 

Being  a  Collection  of  Chemical  Formulas  and  Practical  Manipula- 
tions for  the  working  of  all  Metals;  including  the  Decoration  and 
Beautifying  of  Articles  Manufactured  therefrom,  as  well  as  their 
Preservation.  Edited  from  various  sources.  By  William  T. 
Brannt.    Illustrated.     l2mo.  $2.50 


HENRY  CAREY  BA1RD  &  CO.  S  CATALOGUE.  .r 


DEITE. — A  Practical  Treatise  on  the  Manufacture  cf  Per- 
fumery : 

Comprising  directions  for  making  all  kinds  of  Perfumes,  Sachet 
Powders,  Fumigating  Materials,  Dentifrices,  Cosmetics,  etc.,  with  a 
full  account  of  the  Volatile  Oils,  Balsams,  Resins,  and  other  Natural 
and  Artificial  Perfume-substances,  including  the  Manufacture  of 
Eruit  Ethers,  and  tests  of  their  purity.  By  Dr.  C.  Deite,  assisted 
by  L.  BoRCHKRT,  F.  ElCHBAUM.  E.  KUUI.F.R,  H.  TOEFFNER,  and 
other  experts.  From  the  German,  by  Win.  T.  BRANNT.  28  Engrav- 
ings.   358  pages.    8vo.  $3.00 

;  1DWARDS. — American  Marine  Engineer,  Theoretical  anc 
Practical : 

With  Examples  of  the  latest  and  most  approved  American  Practice. 
By  Emory  Edwards.    85  illustrations.    12010.    .      .  $2.50 

EDWARDS— goo  Examination  Questions  and  Answers: 

For  Engineers  and  Firemen  (Land  and  Marine)  who  desire  to  ob- 
tain a  United  States  Government  or  State  License.  Pocket-book 
form,  gilt  edge        ........  $1-5° 

KIRK— The  Cupola  Furnace: 

A  Practical  Treatise  on  the  Construction  and  Management  of  Foun- 
dry Cupolas.  I'.y  Edward  Kikk.  Practical  Moulder  ami  Melter, 
author  of  "The  Founding  of  Metals."  Illustrated  by  80  Engravings. 
8vo.    (1899)  f3.50 

POSSELT.— The  Jacquard  Machine  Analysed  and  Explained: 

With  an  Appendix  on  the  Preparation  of  Jacquard  Cards,  and 
Practical  Hints  'o  Learners  of  Jacquard  Designing.  By  E.  A. 
Posselt.  With  230  illustrations  and  numerous  diagrams.  127  pp. 
4t«  53-O0 

POSSELT.— The  Structure  of  Fibres,  Yarns  and  Fabrics: 
Being  a  Practical  Treatise  for  the  Use  of  all  Persons  Employed  in 
the  Manufacture  of  Textile  Fabrics,  containing  a  Description  of  the 
Growth  and  Manipulation  of  Cotton,  Wool,  Worsted,  Silk  Flax, 
Jute,  Ramie,  China  Grass  and  Hemp,  and  Dealing  with  all  Manu- 
facturers' Calculations  for  Every  Class  of  Material,  also  Giving 
Minute  Details  for  the  Structure  of  rdl  kinds  of  Textile  Fabrics,  and 
an  Appendix  of  Arithmetic,  specially  adapted  for  Textile  Purposes. 
By  E.  A.  Posselt.    Over  400  Illustrations,    quarto.      .        #5. 00 

RICH. — Artistic  Horse-Shoeing: 

A  Practical  and  Scientific  Treatise,  giving  Improved  Methods  of 
Shoeing,  with  Special  Directions  for  Shaping  Shoes  to  Cure  Different 
Diseases  of  the  Foot,  and  for  the  Correction  ol  Faulty  Action  in 
Trotters.  By  George  E.  Rich.  62  Illustrations.  153  pages. 
ismo.     .  $1.00 


32      HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


RICH ARDSON.— Practical  Blacksmithing : 

A  Collection  of  Articles  Contributed  at  Different  Times  by  Skilled 
Workmen  to  the  columns  of  "  The  Blacksmith  and  Wheelwright," 
and  Covering  nearly  the  Whole  Range  of  Blacksmithing,  from  the 
Simplest  Job  of  Work  to  some  of  the  Most  Complex  Forgings. 
Compiled  and  Edited  by  M.  T.  Richardson. 

Vol.  I.  210  Illustrations.  224  pages.  121110.  .  .  $1.00 
Vol.  II.  230  Illustrations.  262  pages.  I2mo.  .  .  $1.00 
Vol.  III.  390  Illustrations.  307  pages.  i2mo.  .  .  $1.00 
Vol.  IV.    226  Illustrations.    276  pages.    121110.     ,       .  jSi.oo 

RICHARDSON. — The  Practical  Horseshoer: 
Being  a  Collection  of  Articles  on  Horseshoeing  in  all  its  Branches' 
which  liave  appeared  from  lime  to  time  in  the  columns  of  "  1  he 
Blacksmith  and  Wheelwright,"  etc.    Compiled  and  edited  by  M.  T. 
Richardson.    174  illustrations  $1.00 

ROPER. — Instructions   and  Suggestions  for  Engineers  and 
Firemen  : 

By  Stephen  Roper,  Engineer.  181110.  Morocco  .  $2.00 
ROPER.— The  Steam  Boiler:  Its  Care  and  Management: 

By  Stephen  Roper,  Engineer.    1 2mo.,  tuck,  gilt  edges.  $2.00 

ROPER.— The  Young  Engineer's  Own  Book: 

Containing  an  Explanation  of  the  Principle  and  Theories  on  which 
the  Steam  Engine  as  a  Prime  Mover  is  Based.  By  STEPHEN  Roper, 
Engineer.     160  illustrations,  363  pages.    i8mo.,  tuck      .  $2.50 

ROSE. — Modern  Steam  -  Engines : 

An  Elementary  Treatise  upon  the  Steam-Engine,  written  in  Plain 
language  ;  for  Use  in  the  Workshop  as  well  as  in  the  Drawing  Office. 
Giving  Full  Explanations  of  the  Construction  of  Modern  Steanv 
Engines:  Including  Diagrams  showing  their  Actual  operation.  To- 
gether with  Complete  but  Simple  Explanations  of  the  operations  of 
Various  Kinds  of  Valves,  Valve  Motions,  and  Link  Motions,  etc., 
thereby  Enabling  the  Ordinary  Engineer  to  clearly  Understand  the 
Principles  Involved  in  their  Construction  and  Use,  and  to  Plot  out 
their  Movements  upon  the  Drawing  Board.  By  Joshua  Rose.  M.  E. 
Illustrated  by  422  engravings.    Revised.  358  pp.     .       .  #6.00 

ROSE. — Steam  Boilers: 

A  Practical  Treatise  on  Boiler  Construction  and  Examination,  for  the 
Use  of  Practical  Boiler  Makers,  Boiler  Users,  and  Inspectors;  and 
embracing  in  plain  figures  all  the  calculations  necessary  in  Designing 
or  Classifying  Steam  Boilers.  By  Joshua  Rose,  M.  E.  Illustrated 
by  73  engravings.  250  pages.  8vo.  ....  $2.50 
SCHRTBER  -  The  Complete  Carriage  and  Wagon  Painter: 
A  Concise  Compendium  of  the  Art  of  Painting  Carriages,  Wagons, 
and  Sleighs,  embracing  Full  Directions  in  all  the  Various  Branches, 
including  Lettering,  Scrolling,  Ornamenting,  Striping,  Varnishing, 
and  Coloring,  with  numerous  Recipes  for  Mixing  Colors.  73  Illus- 
trations.   I77pp.     i2mo.       ......  $100 


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